Monday, January 31, 2005
I forgot the exact date when I wrote that. I brough the C5 of Paul Ng with my Unistar Light on my small Gitzo, the whole setup is very light but I regret.
I found it hard to use, without my Rigel. The sky was no good that night, a very thick layer of haze is always there.
Okay, this is not a good trip at all, but it serves as a nice proof of concept about going out after family sleep and come back before the wakeup.
Thanks Josephine to give us a free ride.
The sky is nice and clear in the afternoon, we went to Tung Chung to have our short but enjoyable dinner. But when we go outside, we saw the sky full of cloud, anyway, we still proceed.
After the bus trip plus some short relax walk, we arrived and we saw an observing friend Bug who was already there, lying on the floor with his binoculars. The sky was still fully covered. Occasional cloud gap allowed us to spot some stars, but not enough for us to identify the sky. I planned to leave around 8:00p, bad.
The sky cleared up gradually. We scanned through the region near Orion with my C8, and the sky continued to clear up, and in the process, the gone through all the major winter showpieces, like the M31, 35, 36, 37, 38, 41, 42, 45, and a couple of other things like the Christmas tree cluster, etc.
Finally, the sky was covered again around 8:45p and we packed up all the thing, went home rather early, and took our bath well before 10:30p, great indeed.
One of the spikes and rubber feet of my tripod was lost in the trip, got to buy replacement. After some hunting, I found it hard to get other than from the distributor which is located in aberdeen (far far far to me) and need to buy in office hour, not to mention that I have to special order the items. When the annual leave is counted, plus the transportation fee, I end up buying from a UK vendor with about similar cost shipped to me. Finally, it costs me $270 HKD, what a big mistake!
We went there after the fellowshop on Saturday, we belonged to the same fellowship in the church. I took my new C8 Anywhere setup to the church in the afternoon, finished two fellowships and then go there together from Cheung Sha Wan at around 7:15p. The setup is light and I distributed the mount and the eyepiece box to one friend and the tripod to the other, so I can even run a very long distance with the setup! Super good!
We were all rather tired at the beginning of the trip, but I found I owed them for not giving them a peep on the Mars which attracted a lot of people from a very wide spectrum. I owed them before that I who got them attracted by the night sky but without giving them a view through my telescope.
We arrive Tung Chung well before 7:45p, and we bought some easy (cheap!) food and eat them on the way. We waited at the Taxi station and waited for nearly 10 minutes for a taxi, and it is the longest record ever. We arrived Shui Hau at 8:10p, with less than $90 taxi fee, i.e. $30 each, not bad. Personally, I used those fee complimentary ticket (10 trip 1 free) for both MTR journey, that alone saved me
$30+ dollars. You know what, the single trip time is less than one hour, and we are talking about going from the urban center to a dark place!
On the taxi, I can see the whole scorpius hanging outside, it is way better than the urban center. Getting off from the taxi, we immediately saw the milky way extended from the horizon to far above the sky near zenith! This was definitely the best view we had of the milky way!
Setting up the scope takes less than 3 minutes. Extend the tripod, screw the Unistar Lighter mount head in, put the C8 OTA on the dovetail, remove the caps, insert the 40mm XL eyepiece, snap on the Rigel Quick Finder. That's all! I found the Rigel Quick Finder remained aligned with the OTA after nearly two months since the last
M4 was our first target, without good dark adaptation, we didn't get a great view. I switched to M8, and we got a great view! M7 was even more stunning to the non dark adapted eyes. I pulled out the self printed star charts to dig into the milky way and the wonder summer sky!
The Unistar Lighter mount is so easy to use, it is not as smooth as the Giro, but it is not as heavy either. It moves and it stops as desired, which is good enough.
I learnt a new local friend locally with ICQ on the morning. We of course never meet before and we will meet on the same night. Mobile phone reception is not good and I found a family nearby when we're observing, I should aware of that.
Somehow my mobile phone began to roam using mainland network, and I received the call, and confirmed that the family is what I talked with ICQ on the morning.
I offered them some stunning objects and the children were very excited and happy to see the views. The adults are less motivated, but still they enjoyed the view.
I hunted for more objects, including those must-see show pieces like M22/M23, M13 and M11. Hunting couldn't be easier. No single object took me more than 1 minute to hunt. It is easy, and it is enjoyable!
I occassionally switch to my 20mm widescan for double magnification, globulars are better resolved but the view is also dimmer. I found I love larger exit pupil. I found some "noise" in my eyes. Maybe binoviewer can solve the problem? haha...
The list of observed was too long and it was not logged on site. I told my friend that the quality of observation time is much higher than our previous observing location, they all agreed. We hunted, observed more objects that what even ten session of other observation location could offer.
Saying all these, we stayed there for only less than 2 hours since we will want to keep more energy to go to the church on the next morning. Anyway, we hunted for over 20 objects, fully enjoyed.
We left at around 10:00p, walked outside to the bus station, waited for around 15 minutes and then I arrived home at 11:30p. Not bad indeed!
I didn't bring a lot of eyepieces with me. Only the Chinese made 2" wide angle for my C8, plus a 32mm Plossl for my Ranger and a Tele Vue zoom to play with. Balancing is an hard issue since the floor in Shui Hau is inclined. The heavy 2" wide angle is a real problem for proper balancing. I failed to get any point which will allow change of eyepiece without re-centering the target, or tighten the friction control knob of the Giro mount.
Again, deep sky hunting with 8" aperture, plus a 2" wide angle eyepiece, on the Giro mount is a very pleasant experience. Everything was so simple. Look at the chart, locate some brighter stars around the target, aim the rough area with the Rigel Quick Finder, looked into the eyepiece, it's about there, if it's not scan around slowly and the target will be right there within 30 seconds.
Quick and simple and enjoyable! I won't want GOTO of any kind, I mean if I do not go for CCD imaging.
Now, the weakest link in hunting object is not to hunt for it in the sky, but to locate which chart contains it!
Name an object, look up the index, locate the bright star, Rigel, scan a bit, here it is!!! No miss.
Many deep sky objects can be resolved with a 8", what a nice tool to play with!
M4 can be resolved rather nicely, M22, M13 is a dream. M51 shows the parent and the child rather clearly, but no spiral arm yet. M57 shows the hollow ring shape very nicely. M11 is super funny, wild duck!!! Omega Centurie is impressive and fabulous. M6 looks exactly a butterfly, M7 is a gem. M8 shows many nebulousity like M42 in a small scope. M17 is "Nike" in sky! M54, M70, M69 all reveal their
identity under the teapot.
I am sure I saw far more than I can remember. It's just a 2 hours show, time is running to fast. But it won't overwhelm a tired body even we go there after working for a whole day.
We arrived at 6:30p and we setup the 25" scope at around 6:45p. The scope was stored in several place. The secondary cage and the primary mirror was stored indoor. The rocker box plus the primary cage was stored indoor as well, but just outside the roof for observation.
We moved the primary mirror up to the roof and it was very heavy such that two persons can barely do it. This huge chunk of glass was a monster. The secondary cage was much lighter and can be handled by one person. That's important for we got to set it up on the top of the tall tall truss tube.
After the EQ platform, the secondary cage and the mirror was transported to the roof, we moved the monster size component. It was placed on top of a big trolley but we got to move it with five persons.
Setting it up was fun, but time consuming, however it worths. The first installation was not done very nicely and the primary has to be moved out and re-install to get enough room for collimation.
In short, with the 25", all clusters become open clusters. Even the highest density globular was resolved to the core at moderate magnification. The light gathering power and resolving power of the 25" is well shown even with lots of light pollution around.
For nebula and galaxies, it does not show well due to the light pollution, not much color can be discerned, again due to the light pollution, and so we said only 30-40% of the power of the 25" is shown.
All the star clusters, globular or open, show better than photograph since you can see it 3 dimensional. Staring at an object will reveal stars which are not shown clearly in the first glance, and the static cluster looked vivid and alive due to this reason.
I set a goal for hunting five deep sky objects, but I failed. First of all, the moon was brighter and more annoying than I anticipated. I could spot the M44 without problem, and after some hard hunt, I could dig out M3 which is new to me and my friends. Otherwise, all failed.
My friend got a new digital camera and it could be the major source of fun for them. He shooted to Saturn, the ring can be made out, but not cleanly. He shooted the Jupiter, but the excessive shake killed all the detail, not even the equal sign. He shooted the moon, and it gave the best result.
Other than the moon, the mount was a problem. Since I was not that energetic that day, I got only the 410 head with my C8 which is an overload. The slow motion control became very stiff, and it was very bad to hunt for new things.
I should have stayed home to shoot the planets and the moon. LOL
This time, we visit Shui Hau, which is a small village in the Lantau Island, this is also the first time I come to this site. Together with me, we have Leung Sir (Mike Leung), Paul Ng, Billy Cheung (faihoka aka in astrofarm) and Szeto Bug. We gathered at the Tung Chung MTR station at 5:00p but we started off at 5:30p due to someone come late seriously. LOL
Prior to that, I bought my trolley to take my equipments out. I didn't go for a suitcase for some people said suitcase is not robust enough for heavy stuff, and I want to put my mount fully setup during transportation which can save a lot of setup time, I will need a very tall suitcase then, tall suitcase tend to be very large which is hard to move around and excessively bulky for public transport.
I settled for a trolley which is small and retractable, it is rated for 35kg of weight, not bad. I rushed home to pack up everything for the trip within around 20 minutes and go out, eventually late for 5 minutes. Too bad and too good that someone is vastly later than me. hahahaha...
Moving the trolley is not as easy as once I imagine, but it's manageable. I believe I can do better next time. I shall write another article for transporting my equipment to the field. So, let me skip the detail here.
The counter weight get dropped onto the pavement while walking, I then secure it again but that time, it was secured by too much that it was trapped in a recessed position of the shaft and it was no longer movable and removable... bad...
We hired a taxi to go there this time, around $90 each trip. Not bad, but it's comparable to the East Dam which is actually a darker place.
The observing place is rather small, and it is along a narrow single way road and it is a place for car to give way to opposite car. There is only one police car passes by during the whole course of observation. The place is inclined, meaning one will need to spend some effort to level their EQ mount. For me, my GR2 mount and Tech2000 drive does not need leveling to tracking, I was the fastest to setup everything.
For the most night, I keep my 40mm XL in the diagonal, for it is the widest and it provides enough power to see most things. I only borrow some J-ortho from Paul for viewing the planets. I believe I shall get some more J-orthos myself someday later. The zoom has to be used with the Ranger for maximum portability only.
With the Rigel Quick Finder and a set of Telrad finder chart, I managed to clean up two small maps within about two hours. It sets my new personal record. Hunting stuff with the Giro mount is a very pleasant experience. I sweared that GOTO will not bring as much as joy as it can. Don't get me wrong, GOTO is useful for imaging: focus on bright star -> GOTO -> shoot!
Here're the hunted list:
Map 1 (6): M35,M37,M36,M38,M45,M1
Map 2 (13): M44,M67,M48,M46,M47,M93,M41,M50,M79,M78,M42,M43,Christmas Tree (NGC 2264)
Observed list: (hunted by Bug)
Comet 2002v1, Mexico Jumping Star
Chu-kwong arrives at around 10:20p and Paul and I are packing our stuff already by then. What a pity that we missed the ED114SS. Anyway.
We called for taxi for twice and until around 11:00p, we decided to walk to the bus station instead. So, be reminded that it is not a must that taxi will come to this narrow road. And it's better to make appointment with a taxi before hand. Bug was very accurate again telling us the bus will arrive at around 11:15p... nice! We arrive Tung Chung MTR at around 11:50p, so nice!!!!
I love deep sky hunting!
We gathered at 5:30p in Sai Kung and hire a taxi to go directly to the east dam, since the east dam is a restricted area, one cannot go there by other transportation. The sky was very clear all day until around 5:00p, the sky was 90% covered. We go there without hesitation however.
Arrived, we took some shots around. East dam is a very nice place, not only for stargazing but also for sight-seeing. I ate my cup noodle anyway, it was my first time to east cup noddle, I remember to take hot water but I forgot to bring a fork... oops... index finger was used. After taking the noodle, the sky cleared!
We observed a lot of things. Many deep sky objects were nake eye objects! This is probably the first time I saw and pointed my Ranger to M31. No problem. All of us found that there were so many stars under the big dog (cannis major), we didn't realize that before.
It was the first time I found M38 resolvable with my Ranger. Previously I found it was just a faint fuzzy with granularity.
It was the first time I viewed through a Leica 10x50 binoculars. The view was superb, contrasty and super sharpness. It was a bit heavy for a 50mm and the focus travel was limited, the eyecup design was clever and user friendly!
I didn't try to hunt for much new objects, I tried to enjoy instead.
We have briefly polar aligned a spaceboy originally planned to mount a C8 (overload), but the screw does not match (thread size) so it ended up for taking wide field shots with different DC.
Cloud came in around 9:45p, we called the taxi to come back earlier (10:30p originally). When the taxi came, the sky cleared again, but we left anyway.
Popped in the 40mm eyepiece, Jupiter was very white with a slight bit of chromatic abberation due to atmosphere.
Bootup the machine and plug in the webcam, found some seeing problem already. Anyway, took some images.
This time, other than the 2x barlows I've been using, I stacked in the Zhi-tong barlows to get larger view... the seeing was bad anyway, just time to do experiment. The image formed was not bad at all. However, notice that I've the lens of the Zhi-tong barlows removed, so it's just acting as an extension tube!
At such high magnification, I noticed that the backlash value has been set too high for visual observation. I hate tunning backlash during imaging, but anyway, my ToUCam has been stucked up with dust and the dead dot, so, has to place the larger Jupiter more accurate in the use-able field. :P
Call an end to the imaging after a few cheap clips due to really poor seeing, remember Jupiter has sunk quite low?!
Before stopping, I realized that M44 was just a bit lower. Popped that 40mm in again trying to see it... the 40mm was bought for this kind of large object... oh... pink background, and only a few of the stars were revealed... alright, it's the first time I caught the whole M44 with my C8 I suppose... not sure it's because of the larger field of the 40mm, or it's because of the cloud which prune away some stars....
Cheap, but enjoyed! Who cares when you didn't even think it could observe!!!
Choosing a venue alone was not easy as before, since we rarely got chance to observe outside now. We all wanted to get better views, so we narrow down our choices on Shek O' and Tai Mei Tuk and we finally decided to go to Shek O'.
This time, we didn't spend time going to the end of the Big Head Island, instead we settle at a place where the Big Head Island serves as a shelter for the only strong light from far away.
This was the first time we saw milkyway clearly in Hong Kong, it extends rather long in the sky. What a sight!
This time, I took 40lb of equipment myself, and it sets a new record here. I was using the Ranger and the evil lies on the mount, the battery and all other stuff. The GR2-DX was real heavy, and another friend took out his notebook PC for using the roboscope option. The software stowed in my microdrive inside my digital camera, and installing software in the stony place was not a nice experience after all. After several rebooting, we got the software installed.
When the Roboscope PC link was installed, the keys on the pendant will be disabled by then which was bad enough. It was hard to press the keys on the PC lying on the floor while looking thru' the eyepiece at the same time. We failed to do even a two stars alignment in such a bad environment. Too bad that those equipments were wasting our time, and wasting our effort to bring them all out. We originally think it might save our time to hunt down our targets but it turned out to be opposite!
I proposed to turn off all the electronic stuff. The GR2-DX was good enough for me to scan around, finding object couldn't be easier as before, together with the Ranger.
Binoculars observing are always enjoyable. We looked at M7 and then M6, and then M8, and then scan up around to find M22 and those Messier objects near by. I swinged the Ranger to the Antares and it immediately reveals the M4, which I could never see in my apartment even with the 8"! But it shows so nicely with my 70mm right now!
The moon came out around 9:00p and we had a peek on it and then we packed up everything and enjoyed!
The transparency has been excellent yesterday night, I could see over twenty stars despite:-
1. I'm inside home
2. Spot lights are flooding in the sky
3. I've no dark adaptation
When I was doing the alignments (C8 + driven mount), my wife told me that she was feeling sick. I need to unmount everything and took her to the doctor.
Coming back home, I resumed my observation but,
1. Inside another room, with windows closed for air-conditioner
2. Light kept on, for my baby
3. Spot lights are still flooding
4. Nothing to talk about dark adaptation
5. Bright moon was hanging right there
I could barely detect M4, and I understand I shall try to find something else. Instead of the larger scope, I turned to my little Ranger with an non-driven mount.
Having such a small limited window, I scan around exhaustively and slowly.
Finally, I found my old friend:- M7. At 15x, I could see a lot, I mean A LOT, of stars there.
Using the zoom eyepiece, I optimized the constrast by tunning magnification. At one point, I could see that the cluster was three dimensional, dim stars were sinking in the field and brighter stars were floating on top. Woo~~~
Going to another room to fetch in my better quality plossl and ortho, I could see dimmer stars better but it reveals nothing more.
Turning back to the zoom, at 60x, the apparent field of view becomes largest (~55 degree), I could really understand why people shell out BIG money to buy wide field eyepiece. With just 5 degree more, the feeling is a whole lot DIFFERENT! With the increased constrast, even thought I could no loger see the whole cluster, I found it appeared very immensely!
Of course, I shared the view with my wife (she has been better after taking medicine), and she was excited as well.
So, by ALL MEANS observe, since you could see something despite of the bad conditions.
This is the ever best view I had had for my good old friend, M7. I've never been able to spend that many time for a single object, maybe that's why it turns out to be THAT GOOD!
Yesterday night, after searching the comet I-Z (failed), I begin to find a DSO which came near my window.
I used my 70mm refractor to find it, and after looking at the star chart, I found it. It's easy in dark sky but it's not so easy to find it in the urban area. The first time my FoV covered that area which I felt confident in, but there seems nothing there.
I remembered that I read an article from a famous amateur in sci.astro.amateur saying that some objects will not be visible in the eyepiece if you just sweep across the field.
So, I stopped for a while, spend some time to look at the area which I felt confident.
After 2 or 3 seconds, the open cluster revealed itself from invisibility! I called my wife in and showed it to her, she could see if after a while too.
Then, I setup the 200mm and tried to catch it again.
The starting point was Sirius. At 62x, the sky was dark and the Sirius looked real good. I called my wife in and she said it looked like a big diamond. She told me that there's a dark thing in the center of the star, it's an indicator of two things: good collimation, focus was bad. I asked her to focus it again, and the black spot disappeared.
I then searched for M41 again. With the experience just gained with the 70mm, M41 was found much quicker. The number of stars in the open cluster was much more than with the 70mm, and I could see it immediately. Again, I asked my wife in and shared the view with her. She said there were so many stars, with different colors.
Personally, I found the view of M41 superior in a dark sky with my 70mm than the view of it at the urban center with the 200mm. Aperture is not everything, darker sky somehow and sometimes can play a more important role.
This time, I just want to take some afocal shots of the moon. I placed a wooden board over a "bamboo blanket" on top of my soft bed. The tripod could not be extended or else it would be larger than the wooden board. So bad. The setup was top-heavy. I held it by my legs, setup the remote control with the digital camera. Took some quick shots, the results were not so bad. It was a good start.
In short, we found no new object. However, we saw more detail in old objects.
First, Cassini division was very obvious, even detectable without averted vision. This was the first time with my little Ranger. We saw a number of cloud bands as well, they were not subtle. Next to the Jupiter, the GRS was excellent. Perfectly detectable without using averted vision as well. We could detect over 8 cloud bands clearly that night as well. I could also see a satellite coming out from the back-side of the planet.
M42 was fan shaped, we had never detected this shape as obvious as this time. Other dimmer objects were no as nice due to the sub-optimal transpareny.
When we arrived, the whole sky was covered with cloud. We decided to stay a while to see whether there are some other good places for observing next time. It's also nice to breath in some fresh air.
We found another place, but it's not perfect. First, it's too near the road. The head light from the cars can ruin our dark vision totally. Second, we could near nearby towns directly. Actually, our first target of that night was the Central Plaza and the second one was the Tsing Ma Bridge.
Suddenly, we saw the Sirius. We pointed there. Nothing else except the bright white star (not much chromatic abberation with the Ranger, at least not annoying). Next we found the Jupiter. No cloud belts but the four satellites were clearly visible. We tried to find Saturn (which is invisible even with 10x50 binoculars), no luck.
In between the break of the cloud, we looked at M42. And it was one of the worst sight of this old friend. We also found the Pleaides later, and it was visible through both the binoculars as well as the Ranger.
We continued to look from the break of the cloud. Finally, most of the cloud in the zenith went away. We could see two open clusters in the Auriga clearly, and we could actually detect one more, but could not see it clearly. I guess we saw M36 and M37 but just detected M38. M42 and M45 became a fine sight after the area near zenith was cleared. M45 was always amazing. Maybe we should try some afocal shots next time. Saturn's ring and Jupiter's cloud belts were clear. Finally, we found Andromeda beta and gamma (Almach) as well as detected M31 briefly. The double cluster was barely detectable at best.
We could not locate M41 this time.
The view was not good but we were satisfied.
Taking out my Ranger, I want to test the zoom eyepiece in the sharpness department. People said the sharpness drops below 12mm or 10mm. I want to verify it myself. Scanning the sky first reveal many many stars, and it proves to me that the Ranger with 20mm more aperture actually show more, regardless of the night in the High Island Reserviour. It also confirm me that if it's not the dew, the Ranger can actually deliver amazing views under darker skies.
I point my Ranger to the orange star. Strange. I guess my Ranger has pinched optics at first, I also guess that it might be due to the relatively cold weather. The star looks triangular!!! I never noticed that before. My mind is confused and I begin to blame my Ranger again (You know, I'm considering to switch to a Tak FS60C!).
No matter how, I turned my zoom to make it at 8mm, i.e. 60X with the Ranger. Hey! I see two stars!!!! It's not pinched optics, it's excellent resolution!
A familiar view! I saw that in the High Island Reservior!!! It's the Almach, Andromeda Gamma! I can't imagine that the small viewing windows (approximately 10x20 degree at most) can actually show me something!!! Especially in a real urban sky!!! Clear dark sky separate the two stars. The blue star is pinpoint, and the orange star shows it's diffraction pattern nicely, round and clear.
In order to test my zoom, I insert my 5x Powermate to the optical chain. At 100x (24mm), the double split nicely. I dialled all the way to 8mm, refocus. Hey! The stars are separated by a huge gap of absolutely pitch black sky!!! Both stars show diffraction pattern nicely. You know, it's already 300x!!! The little 70mm aperture is showing at more than 100x per inch, I consider myself crazy!!! (Okay, I didn't try to stack my 2x barlows in) Of course, in this setting, the sharpness drops but the image still didn't break down.
I tested my Ranger with the 20mm Tele Vue Plossl as well, the Almach splits clearly during better seeing. Careful observation helps. With the zoom, it also splits at around 18 to 20mm.
I love my Ranger again. I love my zoom as well, it stands up well against the fixed power Tele Vue Plossl.
When I went back home after the prayer meeting, I saw the moon from my windows. I setup the Ranger within one minute and begin observing. The cresent moon was so good in my 15x field of view!!! I could see the whole disc, with the help of Earthshine. I couldn't help to ask my little sister to look into my eyepiece! "Woww!!", was her response. I understand that she appreciated it. I pumped it up to 75x with the Powermate, she looked and wonder how nice the view was. Excellent! I pushed it further up to 150x with the 2x Barlows with the original setup, making it very long, but the view was so good!
I called my parents in and my father found it difficult to catch the view into the eyepiece, maybe the eye-relief was too much in that kind of setup. I replaced it with a 20mm eyepiece to make a magnification of 120x with the Powermate, I knew he could find the view finally when I heard the voice "woww..." from him. My mother got next but she didn't make a woww... voice and we guess that she couldn't see it. But that's not the case, she seemed not so excited as us, she described the view to us, showing that she could really saw the image in the eyepiece. Of course, she appreciated the view, but she found nothing special about it. I guess it's because she didn't know how far out there the moon really was.
I continue to watch the moon, try different magnifications, including the weird 381x and even 762x... To my surprise, the Ranger could hold with 381x actually but of course, it brought no further detail. 762x generated a too small exit-pupil, I could see nothing except my own eyes. Not bad. I keep watching the moon at 75x, finding it's the optimal for tonight. The moon sinked without a notice.
My next target was Jupiter, but I have to wait ten minutes or so after the moon disappeared.
The view of Jupiter was so good tonight, it's the best view I had so far. With 75x, I could detected three belts clearly. Pushing it up to 120x (20mm/5) or 150x (6.3mm/2) revealed the fourth belts. That's the first time I could detect four belts. Actually, I suspect I could see five of them, but I ain't so sure about that. I suspect I could also detect the GRS together with some largest festoons on the thick belt in the "lower" portion of the planet disc. It's so nice that I kept on looking it for 20 minutes or even more, before it went out of the view. The Jupiter disappeared below the tall build in front of me, and I discovered that first when the resolution of the image dropped suddenly.
After all, I found that the Celestron Plossl was the worst among my three eyepieces. The Sirius Plossl was not bad, but a dim ghost could be seen on axis. The quality of the image in the Sirius Plossl was not bad, very much comparable to the Tele Vue Plossl. But I could see no ghost in the Tele Vue Plossl. At first, I guess that the Celestron Plossl plus the Orion Shorty barlows could give some pressure to the Tele Vue Plossl plus the Powermate because there were fewer element in the Orion Shorty, but I found it NOT to be the case. Even the Powermate plus the Sirius Plossl showed me more than the Celestron Plossl alone, i.e. with half number of elements.
I was waiting for the Saturn, it took me the time to write the above paragraphs.
It began to pop into the view at 22:00, the ring opened nicely at a large angle. But I couldn't see the Cassini division, I could at best, say that I could barely detect it. However, I would try to see if I could see it next time. I didn't consider it is success this time.
The little Ranger is more capable than I once think.
This is probably the most fruitful stargazing up to this moment. Among the past sessions, I spent not too many time to explore the night sky when compared to this session. The weather was dewly and the planisphere got soaked very soon. Luckily, the binos served us very well.
Surprisingly, the binos gave me a better chance to look at the night sky. When the sun-set, we first see the bright Jupiter and Saturn. Of course, we could see nothing than the bright satellites and a small disc with the binos. Nothing special for Saturn as well.
As the night moved on, we first looked at the Pleaides and the Orion Nebula. Very good, but they're sort of our old friends. But still, they were impressive. We had a list of new targets tonight.
First, we tried to locate the Polaris. Strange enough, I still couldn't identify this supposed to be easy target after these few years. Maybe it's because I didn't get an EQ mount for my scope, except a very cheap one which had been sold long ago. We soon located the Polaris with the help of the planisphere, and in order to confirm it, we mark its location to see if it moved or not throughout several hours.
We then moved on to look for the Andromeda galaxy. I couldn't locate this one in the last trip which I considered to be a complete failure. I had studied the star atlas for many time to find our way. One of my friends located it first before me. I confirmed from his description that he had found it. Of course, with a hand-held binos, I couldn't share his view. Okay, I tried his method to locate it, and I found it soon. Maybe it's the first time, I found it to be more impressive than the higher praised Orion Nebula!!! We repeated to find it several time and the method my friend proposed was proved to be a nice guide. We extend from the Cassieopia and moved to the direction to a corner star of the Andromeda and somewhere in between, there was a star upper than that straight line, and below that star, we could detect the galaxy.
As the night moved on, we tried to locate the Beehive and it's very nice as well. Other than these new DSOs, we tried to locate some not-had-been identified constellations. It's real nice!
We stopped a while and then we started our trip to the sun raise site. We didn't bring a binos with us, but there're a whole new set of constellations that we could see. And better yet, we proved that Polaris we found was indeed Polaris, since it stayed in its own position after many hours. The bright Venus could be found, but no luck for the Mercury, since there's a bit cloud due east. Not bad, it's a real enjoyable trip.
I switched my target to wait for the Saturn, which is coming. However, the cloud refused to go. Okay, the cloud is still moving. I grasp a view of the Saturn at 120x, not good at all, but it draws old memory.
I better come back tomorrow night.
I could make out four bands tonight. I tried to compare the view through the 6.3mm with 2x Barlows and the 20mm with 5x Powermate. The view through the 6.3mm with 2x Barlows is larger, and the amount of detail in both setting is so similar, and it is not compatible with the result I found yesterday night that the Tele Vue yields a better image.
The Antares yellow filter does help to increase the contrast noticeably, but it also introduces a ghost in the eyepiece. Overall, it's nice to try it out.
I wanted to wait for the Saturn but cloud moved in. But anyway, I decided to wait for a little bit longer.
I have tried to clean the inside of the OTA of the Ranger and some dust was introduced unluckily and after trying several methods, I have successfully removed those dust and it is the first time I used it for observing after cleaning. My cleaning is finally rather successful.
There are many stars when observed with the Ranger, with a 32mm eyepiece. The sky is not dark at all. I would be amazed by the great number of stars before I got the Ranger, but now it is no longer a surprise. Nothing special can be detected, however, when I tried to pump up the magnification on a bright star, I can see the beautiful diffraction pattern, it is steady and nice, perfectly circular. The central solid disc, the first and the second rings are readily observable. What a beautiful sight.
I try to use the Ultrablock also, and it darkens the sky significantly but nothing more can be detected further. There's no magic.
I've made a temporary light shield by wrapping a paper around the objective. Contrast should be improved, since I could see much less stray reflection from the objective side. I've also used a cloth to cover my head during observation to block stray light. However, the light pollution here is just too worst, I could read the star charts without using my own lamp.
Cassini Division was my target, however, only a hint was suspected. By switching among the eyepieces and barlows, I couldn't make it out exactly and confidently. I found it was hard to use averted vision on planets, however, it is easy for the satellite. When I was looking at the planet disc, the satellite (Titan) appeared very clearly; when I looked at it directly, it nearly disappeared. I could see that the ring is rather wide, however, the Cassini Division is still not confirmed. A bit disappointed.
Later in the night, I looked at the Orion Nebula. Before the view was cleared, I looked at the zeta orion. I found that it's a pair of nice double stars, probably my first double star target. The Ranger could split it in 15x and I've tried to push up to 381x and the view was still nice. Good!
The light pollution has affected the whole view of the nebula, and it was quite different then the view in another sub-urban area. The Nebula has become very small, even with the filter and nearly disappeared without the filter. However, by pushing the magnification up to 120x, the view became quite good. When looking at the Nebula at 120x, my attention was caught to the trapezium. I guess it was the first time I really saw the trapezium. Four stars were all visible, and they're covered by the nebula. A very nice view I would say. By pushing it further up to 240x, the field of view became smaller, but not much detail could be seen.
Later for the Saturn, it appeared at around eight O'Clock. I discovered it when I was scanning the little viewing window by using my pair of binoculars and I found a orange small elongated disc. Using the Ranger at 15x confirms the view. I've tried various magnification on the Saturn but not much detail can be seen, just like the Jupiter. I could hardly see its moon, the Titan.
I've tried to use the Orion Ultrablock for both of the planets, since people reported that it could be served as a green filter, I found it not to be the case, maybe the Ranger is too small in aperture. Using the #14 yellow filter could not help to improve the contrast, and however, the light transmission for the filter is high, and I guess it's suitable for my little Ranger. Maybe I should try it later when the sky condition is better.
Tonight, I've also tried to push the scope up to 381x and the image is just a bit too dim to be useful. Actually, even at 240x, the image is not bright enough. I guess 150x or even 120x is optimal.
The window is inside my kitchen, and after setting up everything, I placed a wooden board on the floor to place my eyepieces and barlows. At the first observation, I could see only one barely visible star with my naked eyes. Pointing the Ranger there reveal a pink sky, with a lot of stars, filling the whole field of view of the 32mm. Excellent view! I was attracted, and by scanning around, there were quite a large number of stars available. Turning to the 20mm makes the view of the stars even better for the sky become darker.
In the second observation time, the Saturn suspect appears but after pointing the Ranger there at 15x, I could make a conclusion that I've made it wrong, it's not the Saturn. Instead, I guess it could be the Betelgeuse. Okay, I switched my goal to test my Ranger again. I first pushed it to 381x with the 6.3mm plus the Powermate, the diffraction pattern is not bad, I further push it to 762x, the image is so similar as the 381x, except the star moves so quickly that I could hardly keep it in the field. By placing the 2x barlow before the Powermate, I guess the power is even higher, and yes, the image tends to break down. Anyway, I was pretty disappointed, since I want the Saturn.
Thursday, January 27, 2005
My target tonight was to find the Andromeda Galaxy (M31), since my friend and I were able to spot it in my binoculars in the last trip. I hadn't brought my binoculars this time, which was one of the most important excuse (reasons) that we couldn't find it this time. I guess that it's due to the fact that it's located nearer to the horizon this time. While I were searching for the M31, I found another galaxy which I thought it was the one I wanted. It gave me the feeling for being able to find something, even it's not truely the one I wanted.
Later I looked at the red dot from the Star Pointer, I found the location of M31 should not be that point in the sky. The angular size of the galaxy I found further proved me to be wrong. Looking at the DeepMap 600, I concluded that it was the Pinwheel Galaxy (M33). The sight was good, but it's a bit dim for the 70mm Ranger.
The Pleaides and the Orion Nebula were superb in the Tele Vue zoom. I don't quite affected by the narrower field of view at low magnification of the zoom. Maybe it's because I has not been "spoiled" by the wider-field eyepieces, yet. The view of Jupiter and Saturn were very good as well, at least not a bit poorer than my 20mm Tele Vue Plossl. The zoom capability was really convenient and also useful. Once the target was found, I could zoom in-and-out until I found the optimal magnification. Since clouds moved in occassionally, I found I couldn't see the planets long enough to figure out the real performance of the zoom at higher power. I didn't get a chance to use the Powermate as well, but I've a feeling that the 2x Orion Shorty Barlow might be a better couple with the zoom. The 5x Powermate should be a bit too high, at 100x even at the lowest (24mm) setting with the Ranger.
I also got a chance to watch the sun on the next afternoon using the zoom, the view was excellent. That was the first time I watch the sunspots with my scope, several sunspots (at least seven) were easily visible. I could also look the the detail of each of the spots, and they looked circular with smaller spots inside. So, there were actually several sunspot groups available. I had also taken some photographs with my friend's digital camera, and they can be found at my astrophotography page.
In conclusion, I love my zoom and my Ranger, as well as the new solar filter. Oh, yes... and also the new Gitzo G106 tripod, it was very light and compact, make it extremely portable. So, I sold my Manfrotto 055C in the next week. :)
I think I shall draw a short conclusion after about half a year of usage. The Tele Vue zoom becomes my eyepiece of choice if I have to pick one only. At 24mm, the real FoV provided is large enough for me to find my targets with the Ranger. And at 8mm, it provides enough magnification for me to observe even the planets. Of course, I usually bring the 2x Orion Shorty Barlows or the Tele Vue 5x Powermate along with the zoom. To compensate thing a little bit better, I will also bring the 32mm Sirius Plossl.
In a night with excellent seeing, I've the experience to clearly see the Cassini Division with the Tele Vue zoom at around 120x with the 5x Powermate, cloud bands on the Saturn is obvious as well. I've also see the GRS and many many (over 8!) cloud bands on the Jupiter. More importantly, all these were done with a 70mm Tele Vue Ranger! Averted vision is NOT required. However, I've done it in one and only one occasion. You will never know how your telescope performs until the sky is excellent. On deep sky objects, I've also seen the fan shape of the Orion Nebula on the same night, and that's also the first time.
Unluckily, I haven't brought my 20mm Tele Vue Plossl with me that night, or else I can tell how the zoom performs when compared with fixed focal length eyepieces. But I'm sure that the zoom will not be a disappointment.
And to me, it's an amazing piece of art.
5-Oct-2000: Night and 6-Oct-2000 morning
During the Chung-yeung festival, we want wild-camping at Chek-king. Tonight, I've brought with me only two eyepieces. They're the 32mm Sirius Plossl (to provide me with the largest possible FoV) and the new Tele Vue 8-24mm Zoom. I've also taken the 5x Tele Vue Powermate. After the whole night, I found that the 32mm was left alone in my eyepiece case.
The Pleaides and the Orion Nebula were superb in the Tele Vue zoom. I don't quite affected by the narrower field of view at low magnification of the zoom. Maybe it's because I has not been "spoiled" by the wider-field eyepieces, yet. The view of Jupiter and Saturn were very good as well, at least not a bit poorer than my 20mm Tele Vue Plossl. The zoom capability was really convenient and also useful. Once the target was found, I could zoom in-and-out until I found the optimal magnification. Since clouds moved in occassionally, I found I couldn't see the planets long enough to figure out the real performance of the zoom at higher power. I didn't get a chance to use the Powermate as well, but I've a feeling that the 2x Orion Shorty Barlow might be a better couple with the zoom.
The 5x Powermate should be a bit too high, at 100x even at the lowest (24mm) setting with the Ranger.
I also got a chance to watch the sun on the next afternoon using the zoom, the view was excellent. That was the first time I watch the sunspots with my scope, several sunspots (at least seven) were easily visible. I could also look the the detail of each of the spots, and they looked circular with smaller spots inside. So, there were actually several sunspot groups available. I had also taken some photographs with my friend's digital camera, and they can be found at my astrophotography page.
In conclusion, I love my zoom and my Ranger, as well as the new solar filter. Oh, yes... and also the new Gitzo G106 tripod, it was very light and compact, make it extremely portable. So, I sold my Manfrotto 055C in the following week. :)
This is not the first time I observed the Sun, the last time was a brief look by hand holding the Solar Filter on the binoculars, a few sun spots were detected last time. This time, I observed using the Ranger with the Solar Filter. Several sun spots were detected, with a cluster of sun spots somewhere near the edge of the solar disc. I was using the Tele Vue Zoom through my glass windows (!!!). I knew it's bad but it's an unplanned observation inside my apartment. Not bad, still.
13-July-2000: First Day and Night
- day -
I received my Tele Vue Zoom finally this morning. I bought this one from the Pocono Mount Optics, and I have got a Thousand Oaks Type 2+ Solar Filter for my Ranger as well in this order.
I tested the Tele Vue zoom in board day light, and the chromatic abbervation is obvious. This is due to the semi-apochromatic nature of the Ranger more than the Tele Vue zoom, but I've no way to confirm it since the Ranger is my only scope. The eye-relief is very comfortable throughout the whole focal range. The image is sharp edge to edge. The zoom eyepiece at different focal lengths are not parfocal, but they are closed to be so. Careful observation reveals that there's a piece of dust inside, cleaning on the exposed lens surfaces do not help. Too bad that it lies inside the eyepiece which cannot be disassembled easily.
I just hope that it won't be noticeable at night.
- night -
On the same night, I tested the Tele Vue zoom inside my apartment. It's rather cloudy tonight, but the cloud is moving very fast and so there're sometimes that I can observe the stars in-between the gaps. Stars are sharp to the extreme edge, and the dust inside the eyepiece is not detectable at night, luckily. Maybe it will only appear when I observe the moon. Anyway, I would rather leave it alone than to send it back, since it takes too much time. The apparent field of view is stated as 45 degree at 24mm and 55 degree at 8mm, and I would say it's accurate. To me, 45 degree apparent field of view is not restricting for my taste and the 55 degree at 8mm is nice as well, wider than my previous experience on observations. I only got a few plossls, and maybe that's the reason.
When compared with the 20mm Tele Vue Plossl, the field of view is smaller, as expected. The field stop size at its maximum for the zoom is still smaller than the 20mm Plossl. But the difference is small. I randomly look at the sky, and I can see exactly the same number of stars in both eyepieces, implying that advanced coating make the extra-elements not too bad on the zoom. I tried the zoom with the Tele Vue 5x Powermate and the Orion Shorty Barlow (2x), and they work very well.
On zooming, the apparent field of view expands but the actual field of view diminishes. Close stars become farther apart and the sky background becomes darker as the magnification increases. It's so nice that we can choose the optimal magnification without changing eyepieces. And that's the major reason for why I bought this eyepiece. I couldn't detect any real difference between my 20mm Tele Vue Plossl and the zoom. Maybe I should later try the zoom on the planets, the moon and other DSOs.
This was the first time I tried to pack everything (telescope, tripod, eyepieces, barlows, filters, star atlas) into my backpack. It was rather heavy but still managable. Of course, I still want a lighter setup. Anyway, it's an elegant solution already. I made my observation list in the afternoon based mostly on Turn Left on Orion.
Our observing site was bright. I could read the charts without flashlight (but not read the words) and there was a thin layer of cloud above. Not very good, but it was already a great time for me. My observing list included M4, M51, M81, M82, M13, the Double-double, the Ring Nebula, the Albireo and the M27 Dumbbell Nebula.
I tried to make the list shorter, since I knew that I was still learning. The targets should not be too difficult.
Finally, I got only Albireo or to say more accurately, it's my wife who got it. But that was nice enough, we were amazed when looking at this orange-blue (gold-blue) pair!!!
"I need a larger scope", I thought. But I remembered that my equipments were already quite heavy, I told myself, "I need a darker sky!"
Today is 5-July, when I read the s.a.a newsgroup, I confirmed that my wife and I had actually detected M4, the globular cluster near Antares of Scorpius. Originally, I thought it was fogging of the eyepiece, but later I knew it was there, since it moved with the stars as double confirmed with my wife. After reading from the newsgroup (another guy in Singapore is asking the same question, but he's using a 6"), the description is exactly the same. Good!
30 June 2000 By So King Yan Oldfield
I've never spent that much time which the moon. Tonight, the transparency is bad but the seeing is good. Nothing else could be another target except the bright moon, which is now nicely placed in my little viewing window out of my window in my sleeping room. It looks fuzzy with naked eyes.
I've used my Ranger to do the observation, and it's the only scope that I've after I sold my C90. I didn't miss my C90, since it could not show me anything that the Ranger cannot. The eyepieces which I've used include a 20mm Tele Vue Plossl and a 32mm Sirius Plossl. I've the 5x Powermate and a 2x barlow with me. Therefore, I have 15x, 24x, 30x, 48x, 75x, 120x, 150x and 240x, quite complete. For the moon, I use 75x, 120x, 150x and 240x. I've a light yellow filter (#12) with me as well.
At both the 150x and 240x, I find that my eyepieces are dirty. At the very beginning, I suspect those were my floaters in my eyes. By rotating the eyepiece, I know that it's not the problem of my eyes. By rotating the barlow or the Powermate, the dirts do not move as well, that means I have to clean my eyepieces.
After cleaning the eyepieces, the views are so good. At 240x, the moon drifts across the field of view quite fast, together with the craters on the moon surface. I've a feeling that I'm traveling slowly in a space ship, looking out from the windows. At 240x, the field is not too big and I could only keep looking at a few craters at a time. I found the view at 150x much more comfortable. Adding a color filter does increase
I find that most of the craters are nearly perfect circles, and they are not very deep when compared with their diameter. I don't have a moon map and so I cannot identify the craters, but I find it interesting just to look at them. I have a feeling that I am very closed to the moon, the craters look so large. (Yes, I know they're actually much larger)
Even with a standard Plossl, the field of view is wide enough and pleasing, and I wonder how it would be if I looked through a wide angle eyepiece. Anyway, it's a matter of emotional feeling rather than it is much more useful.
I find that the thin layer of cloud is a not too bad filter. It softens the image produced, but there are still many surface features visible. It darkens the glare even without my own filter, so it comes for free. I find that the moon is too bright even with a small exit pupul, at 240x, i.e. 0.29mm. And since it is so bright, it is a pretty good target for small scopes.
I switched to 75x finally, and the moon fits nicely in the whole field of view. With the Powermate, the 32mm Sirius Plossl produces sharp image across the whole field of view. The edge performance of the Sirius Plossl is not so good without any barlow. The most suitable magnifications are 120x and 150x for the moon, I think. I prefer to
use the 75x for the eye-relief is slightly more comfortable than that of the 120x. I can see the whole field of view in both setting.
Next time, I should come back with a moon map.
Mars will be in its opposition tomorrow night and it's probably the best time, when we put weather aside, for the observation of the Mars for all kinds of observers, especially for those with a small scope.
I couldn't afford to go to a really dark place, I could at my best, trying to go to a place with a sky patch containing the Mars, and allow me to watch for a considerable period of time. My site is mildly light polluted in my sense, or I should say, it's heavily light polluted in more people's sense, since I could read a book there without a flashlight. Anyway, it's not bad for me already.
I have setup everything at around 20:00p, but it's cloudy. Not all the sky was covered, but around 60-70% has been covered. Anyway, I guess I could wait, since the clouds were moving, though slowly. So, I prepared our dinner with my girl friend first. :)
After having the dinner, I occasionally got a short break from the clouds but it's just barely sufficient for me to point my scope to the Mars and then focused, then the view was blocked by the cloud again. It's rather frustrating, but I kept on waiting for better moments. Chats in-between.
I sat on the floor, waiting. And I've gone through the above point-but-no-observation cycles for three times or so. For the best one, I could center the Mars in my 20mm eyepiece and proceed to pick my Powermate up but when I was going back to the scope (I could do all the things without standing up), look up to the sky with naked eyes, the cloud moved back in again. Too bad!
At around 10:10p, a larger break of the cloud revealed. I could center the Mars in my 20mm and I could have a look on it at 120x when coupled with the parfocal Powermate, very convenient. At the first sight, I remembered the words that I've read from the past saying about the experience of observing the Mars, "It's probably the most frustrating object". Yes, a boring orange disc, showing virtually nothing. No polar ice-cap (later confirmed that it's not there at all, since it's summer at the facing side of the planet), no canals, it seemed that there's nothing there. Just a large color disc.
Yes, the sky was not so clear. So, I tried to lower the magnification to 75x, by using the 32mm with the Powermate. No major improvement except the image was brighter. Less waves of air were observed at this magnification than that at 120x, that means the seeing was bad as well. I knew that I've to be patient to wait at the moments with better sky conditions. I tried to use the #12 filter with the 20mm as well, the 120x view was not improved. I have also tried to pump up to 240x with the 20mm, Powermate and a 2x barlow, but the image could neither be improved nor be broken down.
Chromatic abberation was quite noticeable for the Mars at its opposition. When the focus was correct, the image was quite good; but a slight out of focus image was no good. Obvious red or purple shadings were seen around the planet disc at both sides of the inexact focus, making me think of seriously considering to upgrade to an apochromatic. :)
Actually, I could detect some hints of black markings on the disc, but those were not obvious and I didn't feel satisfied. It seems that I've to try again asap.
26-April-1999 insert: The polar ice-cap(s) is not visible at that night since it's not there at all. And as people reported, the surface features on the Mars are not as constrasty as those in the Jupiter or in the Saturn, so maybe it's really a frustrating object to be avoided. Anyway, why not have a try later?
This is the first night that there is at least some un-cloud-covered areas in the sky since the arrival of my new discounted Orion Ultrablock and an Antares #12 yellow color filter.
I rushed to my observing site since the Orion Nebula will be out of sight range after 21:00. Luckily, I could get 8 minutes of observing time with the Orion Ultrablock. Since I would like to test the filter with greatest chance of getting a look at the Orion Nebula, I have threaded on my filter immediately. Looking at the Nebula reveals
a fuzzy patch, by removing the filter, I noticed that the condition is not so good for tonight, since the fuzzy patch nearly disappear after the removal of the filter. It's not the case before. Therefore, I could see that the Ultrablock is quite effective even when the condition of the sky is not so good. Let me see if I've chance to test again later, in a darker sky. You know, the sky is bright in my observing site. I could read a book there, so imagine how poor it is.
Then, I begin to try out the yellow filter. Since there's no planets with my range, I choose the Sirius. The yellow (with the filter) star is pretty and chromatic aberration is not very noticeable after using the filter. However, when I move the focuser a bit, I could see the color of the star change! Now, I see how a color filter helps us to
get good focus.
Orion Nebula Again, 10-Feb-1999
Just found that I could see the Orion Nebula in my small viewing window. Without the filter, only a hint of fuzziness can be seen.
With the filter, I could see much more fuzziness. I would say the result is very good. However, for the heavy light pollution, the viewable size of the nebula becomes rather small and so the same effect of the filtered view can be obtained by using a higher
First and second nights of observations
I thought that it would be an exception today, since the sky was still sunny in the afternoon - I've received my new Tele Vue 5x Powermate. Cloud began to move in, after 18:00. I tested the Powermate anyway, but not on stars, just some lights and buildings.
My first comparison was 75x, offered by the 6.3mm Celestron Plossl and the Powermate plus 32mm Sirius Plossl. Before the test begins, the first winner would definitely be the Sirius Plossl for the eye-relief. Actually, what I was interested, was the light throughput, and the contrast. In the Powermate system, we have eight elements in four groups; and in the straight plossl, we have four elements in two groups. My target was a cable tower far away, there were no lights nearby. The images produced were nearly identical, the FoV produced were similar as well. I could make out the structure of the cable tower in both setup. Careful examinations reveal that the FoV in the Powermate system was better, and I conclude that it was not due to the slight magnification difference but it was a result of eye-relief. I don't know whether it's a pyschological effect or not, the straight plossl looked slightly brighter. I was not sure though, anyway, it's so similar.
Next I tried the Powermate with the 20mm Tele Vue Plossl. "It's wonderful!", I would say. After centering the view with the 20mm alone, inserting the Powermate immediately gave me a sharp view! Now, I see what's meant by parfocal! The view was bright and the image was so constrasty and nice! Next, I tried to test the 32mm Sirius Plossl with the Powermate and quite disappointed, I found that the Powermate is not parfocal with the 32mm Sirius Plossl; similar result were obtained with the 6.3mm Celestron Plossl, no luck. Tele Vue has successfully attracted me towards a 32mm Tele Vue Plossl as a future upgrade.
I have also tried to use the Powermate before the diagonal, again it couldn't be focused with any of my eyepieces. My last test were the 6.3mm Celestron Plossl with the Powermate, simple calculation told me that it yields 381x, which was too much for such a small scope. I had tried to push the C90 to 317x and the image was already broken. Surprisingly, the 381x image in the Ranger was not bad at all, except it was too dim to be useful, all the detail were still there and I would think this magnification would be useable with brighter objects like the moon, the Jupiter (tested later to be okay, but a bit too dim) or even the Saturn. Great little scope.
Finally, I found that my 6.3mm Celestron Plossl might have negative eye-relief, since I couldn't quite see its whole field even I had pressed my eye to the eye lens. Now, the Powermate with the Sirius Plossl gave me a nice alternative, without real noticeable difference with the straight plossl.
A star test would be performed once the sky is ready.
I was lucky that I've got a chance to test my Powermate again in the next day. The sky was not very clear, but quite a number of stars were visible. When the eyes were a little bit dark-adapted, it was possible to see the whole Orion.
My first target was the bright Jupiter. By using the 32mm with the Powermate, I got 75x which was so nice. The image formed was very nice in that kind of seeing condition. Four cloud belts were visible, though not very clear. You know, I was so happy that since it's so more comfortable than the 6.3mm. Next, I tried to use the 20mm with the Powermate, and it yields 120x. I would say it's the optimal (or something in between 120x and 150x) for the Ranger at high power. Even the power was not as high as the one produced by the 6.3mm in 2x, but the view was absolutely comparable since the image was brighter at 120x.
My next target was the Saturn, which was near the Zenith. Pointing to this kind of bright targets were very easy with the Star Pointer. The images produced by the Powermate with the 32mm and 20mm were 75x and 120x respectively. Being parfocal, the 20mm was one of the most wonderful experiences of using the Powermate in my present eyepiece collection. Cloud belts were suspected, since the view was limited by the poor seeing and transparancies.
I then proceed to get even higher power by stacking the Orion Shorty 2x to the Powermate, yielding 150x and 240x with the Ranger, by using the 32mm and 20mm respectively. The images produced remained so nice in both settings, but bad seeing limited everything. The Cassini division and the GRS (later confirmed that it was out of sight at the time of my observation) were not noted, probably because the environment was so badly light polluted and the seeing condition was just marginal.
I had also tried to use the Powermate with the 6.3mm at the Sirius to check the chromatic abberation of the Ranger (it's 381x), too bad. It was so colorful, but I don't need to get such high power with the Sirius anyway.
Finally, I would say, it was a wonderful experience. After this test, my desire of getting more eyepieces were diminished a lot, since I got a lot from the new Powermate, the existing 2x Barlows and the two eyepieces.
Lastly, I guess I must have tested that 381x on the Jupiter or the Saturn, but I hadn't. Another test should be conducted later when the sky is better.
* It undoubtly transforms my long focal length eyepieces, with their long eye-reliefs, into short focal length eyepieces
* It brings your small focal length scope into a much longer one, even with a 400mm scope, you got a new 2000mm scope with the setup time of several seconds
* It has got a real small aperture, and the light cone is narrow anyway
* I got no chance to compare with short focal length eyepiece, for the long focal length eyepiece and powermate combination, except the 6.3mm Celestron Plossl, which is supposed to be not very good anyway.
* The property of being parfocal is an excellent feature
* This kind of four elements optics should be more profitable than the Plossls, in Tele Vue's point of view
* Stacking barlow is no problem, at least for my eyes
* I guess it is useless for common SCT having more than 1500mm focal length already, but how about the 2.5x Powermate?
* BUT it is a must for short focal length refractors, particularly those from Tele Vue
This time, I have brought out a chair for the observation, setup everything in a more comfortable manner. The sky appear to be pink, which was a sign of severe light pollution with a thin layer of haze. Never mind, the Saturn is just ahead near the Zenith, which is the only observable location from my home. With naked eyes, nothing other than the Saturn was visible. Bad? However, it is the astronomy in Hong Kong.
Without hesistation, I tried to point my scope to it but it's a kind of difficult. I installed the Celestron Star Pointer and turn it on, align the red dot with the Saturn. Okay, it was inside the eyepiece. At 24X, the Saturn appears to be an elongated star, and with imaginations, I could make up the ring. By inserting the barlow, the ring stood out. A nice view to me, even after watching it through the scope for many
I tried to insert the 6.3mm Celestron Plossl to get 76X, this time, the view was good. It is certainly more contrasty than that with the C90 and 12mm Celestron SMA. This time, I clearly saw that the dark gap between the planet and its ring. I tried to see if there're some cloud belts observable on the planet surface. I was not quite sure this time, but I guess I could see two of them. By pushing it to 152X with the barlow, the view was a little bit better, but I wonder if it's just the result of a larger image or not. I still couldn't make sure if I could see two cloud belts or not.
A good finding in this observation is that, the Celestron Plossl is not that bad in terms of clarity of the image produced, but the eye relief is really terrible, it is essentially zero. To have good eye-relief, I guess the only way to go is to buy those really expensive ones like Pentax SMC XL or the new Tele Vue Radian, or to buy the Tele Vue 5X Powermate to couple with longer focal length eyepiece.
After this observing session, I found that focusing at 152X would make the telescope shaking but the Manfrotto (Bogen) setup can become steady within one or two seconds, so it is nice. Tracking is no problem as well. However, I discovered that the draw-tube design of the Ranger is not so good, since when using the Ranger for objects near the Zenith, it tends to move, I wonder if I could use those heavier eyepiece with it or not. I don't want to over-tighten the screw.
My present estimation is that, I should not push the Ranger to over 200X for the steadiness of the view and something around 120X to 160X should be the optimal high power range.
I was originally trying to observe the Jupiter, and I waited until 1:00a with no luck. It seems that the orbit of Jupiter had moved out of my observation range. I tried to look out in the window and I could see a bright star with my short-sighted eyes. I guess it was the Jupiter. Then, I tried to look out in another window of another
room. Oh! I could see the Jupiter. Notice that I could only observe in the first room I've mentioned, i.e. the Jupiter had moved out of my sight range. It's a bad news to me.
When I walked back to the first room, I was thinking of what's that bright star? Oh! It should be the Saturn! My hope revived. But it is still too high to point my scope up, with the shelter out of my window. For the first room, I could go out from the Windows and there's a small place that I could place my scope there, but I've to
take the risk of being treated as thief. Anyway, I dare to watch the Saturn with my new Ranger.
Finally, I had decided to take the risk. I used the 20mm to locate it first. I found that it's too difficult, and so I've installed the Star Pointer to have a try. Yes! I got it in the 20mm. It looked like an elongated star. After playing with the helical focuser, I could make out the ring at 24X. Then, I inserted the barlow. The view is
so nice! And this 48X view was equal to, if not better than, the 83X view of the C90. It guess it's because the scope and the eyepiece were better.
I was not satisfied, and I moved on to use the 6.3mmn to get 76X. The view is not as constrasty and as sharp with the TV Plossl. Maybe the seeing condition did not allow, or the Celestron Plossl is inferior. I guess it was the former. Anyway, out the curiosity, I tried to insert the barlow anyway. I found it's kind of difficult to focus,
and could it be an evident that the seeing was no good? I guess it should be.
By using higher power than 48X, I found nothing more than a larger and fuzzier ball. I shared both of the view with my little sister, and she's so impressed. Later I confirmed that she never had any telescopic view of the Saturn before.
It seems that I should find a better night for another observation, but what I found was that, the Ranger is a so nice little scope.
The Jupiter was already at the boundary of the observing window, and therefore, I've to work quick. I point the scope out to the window and soon I found that bright dot of light. I used the Tele Vue 20mm Plossl and I could see the surface bandings. By inserting the Orion Shorty Barlow, I could see more clearly. As described by the manual of the Ranger, all the resolution of the Ranger can be seen theoretically at 40x, which is similar to the 20mm Plossl with barlow. However, it also states that it would normally require 80x or 120x to view it clearly.
I then proceed to the Celestron 6.3mm Plossl and I got 76x, the disc became bigger. And I could see the Jupiter was moving easily. I've also tested it with the barlow on, and the bright giant gone suddenly.
I realized that it's gone below the building at the front.
Now, it's proved that the Ranger is really portable, with the tripod and it can be setup very quickly.
When it's 7:15p, I went up to the roof to have a look. Woo! It's full of stars. The scorpius was still there, but when I looked at the heart of the scorpius, I noticed that the air was not so steady, since the red star was twinkling. Anyway, it's already one of the best night for observation after getting my Ranger.
What a complete falure was that, I had forgotten to plan my observation. There were lots of stars in the sky, but I had no idea about what I was going to point my scope at. I tried to find the double stars in the scorpius, but I failed to find them, since I've forgotten exactly where was it. I tried to locate the Andromeda Galaxy, but I failed too. I tried to locate the Saturn, and again, no luck. (Finally, I checked later and realized that it's not yet in an observable location.)
Finally, I've looked at the moon, which was more than a half-full. The view was nice in my 6.3mm Celestron Plossl Barlowed, and it was better than the last time I saw, the boiling water effect was not very apparent. It reminded me for the last experience, which gave me a feeling that I was flying inside a space craft, looking outside the windows. Next, I've tried to look at the Jupiter, and I could pick out the two dark bandings with the 20mm Tele Vue Plossl, while my little sister said that she couldn't. Maybe that's experience.
Then, I tried to use the 6.3mm Celestron Plossl Barlowed, yielding 152x and I could see one more banding, at least. Two thicker ones and one thinner lying near on the outer side of one of the thicker bandings, were what I saw, excellent. I wish that I could see the GRS next time.
Last time, I found that I simply couldn't put the three Galileo satellites into the field of view of the 6.3mm Plossl Barlowed, however, I later realized that it's due to the insufficient eye-relief of the eyepiece, so that I've to put my eyes real close to the eye lens to take into the whole field of view. I've tried it out and I found that I could now put everything of the Jupiter into my eyepiece! It's a good and new discovery. This time, I found that the 6.3mm Celestron Plossl was not as bad as I once thought, except the short eye-relief. It seems that my next move should be getting a higher power barlow (the Powermate?) and a longer focal length eyepiece, say a 12mm and to use them together as a replacement of the 6.3mm, so that I can have more eye-relief. Or another alternative is that, to get a wide-field eyepiece, which requires a lot more money.
Lastly, I've found a nice point of refractors (un-obstructed scope) and that's a darker sky and brighter stars. I've also found a weak point of (non-APO) refractors, it's the chromatic abberation problem in brighter stars. However, I found that it's not a problem for extended objects like the Moon and the Jupiter, however, it's obvious in the real bright stars. And I found it nice to use higher magnification for brighter objects, since the view would become dimmer so that I can pick up more detail. But does it implies that I don't need those (color) filters now?
I spend most of the time to look at the Moon, and it's exciting enough. With the highest power available (2x barlow + 6.3mm Plossl), I can easily see that the moon is moving, I've got the feeling that if I were on an space-craft, flying slowly and watching over it's surface. When the wind is coming, I can see the air ahead moving, just like boiling water. To me, I've a feeling that it should be nothing too special, however, it's a new experience for a C90-only owner. I can never see all these before. Many surface features are detectable and they're nice.
Another *new* discovery is that, I can see many many stars no matter where the telescope is pointed to and it's never the case for my C90. Now, I see optical quality wins, even aperture wins too.
The Star Pointer from Celestron work nicely and it can be quite accurately aligned, and the Manfrotto 410 head is excellent too. It's a bit too tight in the first hand but it works great once I use it more - I've already used it *more* enough. Now, I think I've got a decent setup for more serious observing.
Chromatic abberation is serious for the Ranger in day time, but strange enough, when looking at the moon or the stars, the problem is not so severe. I can neglect this problem virtually, since my eyes cannot detect it too much in night sky. Many people don't like the draw-tube focuser of the Ranger, however, I find that I love it and the helical focuser, is smooth enough, but the focus travel is insufficient. Of course, when it's used with the draw-tube, it's definitely enough.
Tracking with the geared head is no problem at 152x. It works nicely even when the Ranger is pointed at the Zenith, no balancing problem at all. When moving the adjustment knobs, it shakes but the vibration damps out quickly.
With the 32mm Sirius Plossl, the view is large and nice. I can never have similar view with my C90 but I find wide field view is still better with the Pentax 10x50, however, it's comparable. The edge performance of the 32mm Sirius Plossl is better than that of the Celestron SMAs, but it's still not up to the level of the 20mm Tele Vue Plossl. The field of view with the 20mm Tele Vue Plossl is nice too, but it's noticeably smaller than with the 32mm Sirius Plossl. The edge performance of the 6.3mm Celestron Plossl is good too, but again, not up to the level of the 20mm Tele Vue Plossl, as expected.
Next time, I should try out some deep sky objects as well as the planets.
This short project is defined based on the fact that Jupiter will pass into my observing window at my home every night approximately during the above time period. So, it is so convenient for my to observe it without going out. Apart from this motivation, I can obtain more experience on observation and this is possibly a good step to begin
with some more serious observation. At the same time, I could get more knowledge on my Ranger to see what is the best way to upgrade it with more accessories. Lastly, planets may be the only possible targets for city observations.
Today, the air looked steady, however, when going up to 152X, I could notice that it's not the case. I should say, I could detect every bits of the observable detail at 76X and by going to 152X, I just get a bigger image.
This time, I could make out the three major belts and a hint of some minor belts at 76X. By going up to 152X in the hope of getting a better image, I still couldn't sure the existance of the minor belts. I suspected that I have seen the Great Red Spot as well, but I was not sure about it. At least it must be some kind of storms in the
At 152X, the image sharpness varies over time due to unsteady atmosphere. At 76X, the detail seems a bit too small for my eyes. I guess I need something around 120X (20mm + 5X Powermate), and something like 180X for an even larger image.
Tonight, I understand that stable and good breathing is one of the key to observe more detail. People tends to hold the breath when the view is fantastic.
I planned to use my C90 for observing tonight, but thing goes wrong.
Nothing goes wrong with the sky and my scope, but it's just that I've missed the view since I've got a phone call at that time. Anyway, I got the 50X view before the Jupiter disappears. Maybe tomorrow.
Before the Jupiter appears, I've tried to test the C90 again with various eyepieces, with or without the barlows. I've conducted the test with the brightest star available in my observing windows, but I can't identify the star and I guess it's not important.
At up to 100X, the star image is still okay. However, by going up to 159X with the 6.3mm Plossl, the image becomes very dim and slightly blurred; and by inserting the barlows, the 317X image seems couldn't be focused and it remains as a fuzzy light patch.
Tonight, I've setup my C90 to wait for the Jupiter to come in. As expected, it appeared 3 or 4 minutes earlier when compared to that of the first day I observed it. The sky was not as clear as before and it looked pink.
With the C90, I could see the belts on the planet surface at 50X, with a little bit difficulty. I guess I couldn't see them when I still haven't got my Ranger, maybe experience has been improved.
(March 1999 insert: I guess that's more because of the fact that that time I was observing at home, and the C90 could have been rearch thermal equilibrium, while I didn't notice this problem before, when I was observing outside. Still remember that the cloud belts were obvious, and it should not be a problem of experience, of being able to see it or not, at least it is possible to detect them by any untrained eyes)
At 100X with the 20mm Plossl with barlows, the cloud belts were clearer, but still not as contrasty as the Ranger at any magnifications which were enough for making out the belts. Pushing it up to 159X with the 6.3mm makes a bigger and more fuzzier ball, further trying it at 317X, I could not get a clear image at all. I've also tried
to observe at 62.5X, with the 32mm barlowed, not bad.
I switched to the Ranger before the Jupiter went out of view, the views are more constrasty and the cloud belts appeared to be more clearly. I conclude that the Ranger is by all means better than the C90, and the image remains bright up to 152X, even the light gathering ability is not as good as the C90. And with the same seeing conditions, the Ranger outperforms the C90, however, at the about 2.5 times the cost.
The Jupiter appeared two minutes earlier than today, and it fit nicely with my prediction. There was nothing planned except trying to remove the lens from the barlows to thread them directly into the eyepiece barrels. As expected, the magnification factor was reduced, which is not bad. I guess I have to check the magnification of that configuration to allow a more flexible range.
Tonight, the seeing condition was not as good as it looked because I could see the "boiling effect" in the image of Jupiter at 48X. Occasionally I could see the belts. Increasing to 76X, the image didn't improve but it's as expected; and 152X was totally useless.
I remained at 76X for most of the time, and soon I discovered some glares along an axis, and I tried to rotate the eyepiece in the focusser and I conclude that it's not due to the defects of the eyepiece; I switched to the TV Plossl and the problem remained;
and I didn't know why.
Until this morning, I guess that it must be due to the straying light outside my viewing windows. Let me check if I could make a glare shield to improve the situation.
I rushed back home today for the Jupiter, and it's already there when I arrived home. I setup the scope quickly within one minute and begin to look around. At 76X, I could already notice that the air were moving like a stream in the river. I raised
the power up to 152X and wait when the turbulence to stop for a while. Yes, it stopped occasionally and I could see more.
Anyway, I tried to train my averted vision. I found that I could see better when I look at the right of the target. And I found that the glare can be eliminated and rotated by wrapping the hand around the lens cell.
Either the weather or my time didn't allow, and I've paused for quite a while. Tonight, the satellites of the Jupiter are aligned at one side of the planet and I counted four of them. The air is not that steady, boiling water effect can be noticed at 76X but I could still get some steady views at 152X occassionally.
Some ideas about observing: I've tried to shrink a picture of the Jupiter (from HST) in the computer to model the view in a telescope. However, I found that I could hardly detect three cloud belts with an image of similar size to my telescopic view at 152X. Maybe the resolution of the monitor is not as good as the Ranger. Originally, I would like to try out the optimal power (or minimum power for more detail) by this method,
but obviously, it sucks.
At about 21:30p, I went out for a football court for a relatively "darker" sky. Spot lights from another football court were shinning within 1km, and so I didn't expect too much. No matter how, the Jupiter can be seen at that moment. I set up the Ranger within two minutes, it looked that the Manfrotto Triminor tripod + Junior Geared Head is so nice and easy to use, except it's a little bit too heavy and lengthy.
I switched on the Celestron Star Pointer and try to cover the Jupiter with the red dot, done! I looked into the 32mm Sirius Plossl and Jupiter was in the view! It's good, I can see three of its satellites, while it's expected since I can see it even in my Pentax 10x50. Jupiter appeared to be a small disc with trace of non-uniform coloring. And that's the view of Jupiter in 15x.
I would want to try the Orion Shorty Barlow out, so I inserted it between the 32mm Sirius Plossl and the diagonal to get 30x. Yes, it worked nicely and I could roughly detect the two darker cloud belts. I later tried the 20mm Tele Vue Plossl with and without the barlow, for 24x and 48x) the view was nice and the disc was getting larger but not much more detail could be detected, for the sky was not so clear.
Finally, I tried the 6.3mm Celestron Plossl with and without the barlow, to get 76x and 152x. As expected under this kind of poor observation condition, except a larger disc, I could not see more detail at all. The satellites could not be fitted in the same field of view and I could notice that the edge performance of the 6.3mm Celestron Plossl is not so good. The target drift out of the field of view easily. I guess I have to get a better high power eyepiece later.
I could not detect the cloud belts in my C90 before, and it was a new and interesting observation to me with the Tele Vue Ranger. I would try to look at the Saturn later when it's higher in the sky, and I would want to look at the Jupiter again in a better observation environment or condition.