Wednesday, December 26, 2018

20181226 Sun


0827 (UT), the solar surface remains boring, except a small active region on the upper right, and a few small prominences.

Ranger with Solarmax II 60 with BF10, with the reducer on.

Friday, December 21, 2018

Chuwi Lapbook 14.1

I've a cheap Chuwi Lapbook 14.1 laying around and it could be used for astronomy purpose.  The first thing I will need to do, is to expand its storage, so that it could store more images or even video from Sharpcap.  This is only possible with the earliest version of the model which comes with a m.2 slot, later versions have it removed silently.  On simple disassembly, I found that I am lucky enough to have the original version!

I got a really cheap one from taobao, and it has 128G in size, which is about right in terms of price and size!  It makes no sense to buy something expensive for a cheap notebook!  128G will triple the original size!  This SSD has a form factor of 2242, but it also comes with two detachable parts for better compatibility with bigger form factors.


Windows managed to detect the SSD without problem, and after simple partitioning and formatting, it's ready for use.


A quick speed test was conducted in Sharpcap, it's way faster than the original internal SanDisk eMMC!



In addition to my Voyo, this Chuwi could be used as well.  I suspect it will yield higher fps than the Voyo which features a faster CPU.

Saturday, December 15, 2018

20181213 水浪窩 雙子座流星雨?

其實未出去已經知無景,不過算係去散吓心。


雲不散,不概嘆,早已慣;早一晚,藏山間,靜無限。

Canon 450D modified, 20s exposure at ISO 800, fixed tripod.

Minimalist style camping, less than 9.2kg total.




Tuesday, December 04, 2018

20181129-1130 Modified Canon 450D first light (Camping in Chek King)

I went for a camping trip and astrophotography was only a very small part, so I used a mini-tripod with a small ball head only, and I only had my Canon 50mm f1.8 with the modified 450D.


To keep the story short, I found that the 50mm f1.8 could no longer reach infinity focus when the IR filter is removed!  The 50mm f1.8 has very limited focus travel, and this is the problem.  Notice that it's not autofocus that fails, this is anticipated due to the change of the optical path length.

It's one of the best night for the last decade, luckily I've my Canon 10x30 IS with me and I enjoyed tremendously!

Sirius with M41, I love to catch the view when it's still low in the sky, the tree as foreground is very nice!


M31 at the corner.


M45 hanging just above the trees.


The Orion and M42 just went above the tree!  Note that red color on M42, it used to be purple before.


Later I found that if I insert a CLS filter between the lens and the camera, it will reach infinity focus again!  Next time I shall try this one combination out.

For wide field, maybe my Canon 70D is better due to the movable LCD, composition should be far easier.  The modified 450D might be better for targets richer in H-alpha.

Sunday, November 11, 2018

20181111 Sun

The sun surface is still quiet, 0653 (UT), taken with reducer on:


But on carefully second look, you could see two small prominence at the 1 O'Clock and 7 O'Clock direction.

So here are two shots with 5x Powermate, and reducer removed.

First at 0701 (UT):-


And then second at 0706 (UT):-


The Solarmax is not very good at imaging these.

Monday, November 05, 2018

Canon 450D modifications

Canon 450D is my first DSLR.  But after I got my 70D, this was left idle.  I always want to remove its IR filter astronomy purpose, but I never got the time and courage to do that.

As the price of 2nd hand 450D is dropping, the initiative is getting bigger and bigger.  In order to unleash its residue value, the modification is the only way to go.  Earlier this morning, I took the plunge to carry on the modification according to the information on the web.

However, those pages were updated as newer DSLR comes into the market, and thus some photographs along with the instruction might not be very helpful.  Some guess work required.

The most difficult trouble to me was those screws.  I simply couldn't remove a few of those screws, they literally screwed up!  I had to use a drill to remove them completely in an irreversible manner.  I met maybe four such nasty screws.

Here are some snapshots, the first milestone as below with bottom and back cover removed:


Next, when the daughter board was removed:


And then the metalic cover on top of the CMOS assembly:


And then the CMOS assembly:


The shutter could be seen above, and the CMOS board below.  A cutter has to be used to remove the first filter.  The first filter serves as the dust removal system and this was to be kept.  The second filter was the one to be removed.  And below that was the CMOS.


I did removed the filter, but I didn't take any photograph of it.  I placed it downward to prevent dust from falling onto it.

Re-assembly is easier but still quite difficult.  I managed to leave a few screws unused, but then the camera works without problem, no loose parts.

This is the first shot taken after the modification!  The pinkish hue is so lovely!


Finally, I had set the internal parameter for astronomy purpose.  Turn on RAW mode, remove any built-in noise reduction, turned off the flash by default and so forth.  Wish to use it in the field soon!  Together with the DIY external power supply, this is going to be my work horse under starry sky!

20181105 0644 (UT) Sun


As title, the sun is still very inactive with a dim filament on the upper right, and it seems to extend to the limb as a small prominence.

Monday, October 29, 2018

20181029 Sun

The sun comes back to my observing windows! 


But it's solar minimum, dead silent.


Taken at 0553 (UT), Ranger with reducer, Solarmax 60 with BF10, ASI 120mm.

I've tried to push up the image scale with 5x Powermate, but again nothing except a few interesting magnetic pattern.

Saturday, October 27, 2018

20181027 Mars

The Mars is getting farther, dimmer and also smaller.

Pulled out my 85mm ED refractor, and 5x Powermate, ASI 120mc.

This time I reduced the ROI to 640x480 and the frame rate goes over 38fps!  Very nice indeed!

The Nexstar mount is very stable now, vibration damps out very quickly and I don't need electronic focuser any more!


Taken at 1410 (UT), 1.5x Drizzle.

Monday, October 08, 2018

20181007-1008 Camping and wide field imaging

Camping means heavy gear, you have a tent, cooking stuff, sleeping stuff, food, water, etc.

Stargazing is never light weight as well.

But I'm trying to combine these two, and I don't have a car.  I've to rely on public transportation which means very limited access both in terms of location and time - the last bus could be as early as 21:00 so that I won't have much time to observe if I had to go home.  So, it would be nice to stay overnight.

This time, I choose Shui Long Wo (水浪窩), which has better access, the last bus would be 00:00 so that I could go even after dinning with my family.  With heavier gear, the location could be reached in less than 20 minutes walk.

Water source is not too far away, but the supply could be unstable.  The toilet on the roadside could easily ran out of water due to the heavy usage from the nearby BBQ sites.  There is another water source up there in the middle of the way to the campsite, but this one could go out of order as well.

Since this is just a test of the concept trip, I brought only a DSLR with a fisheye lens on a camera tripod.  I've 15kg of stuff together with 5kg of water acquired in the middle of the road.  I believe I could further trim down the weight by 2-3kg.

The first one was taken before midnight at around 22:30, light pollution was serious.


The second one was taken around 3:00am, the dark was darker.


No more than 20s exposure could be used, or else the screen would be saturated.

It would be a bit too soon to conclude that this site is no good, since you could thin from the above that a thin layer of cloud/mist was there.

Friday, October 05, 2018

20181005 Sun

Solar minimum that it!

Half day off today, so I pulled out my Ranger with Solarmax 60 and BF10 for a short imaging session:



0542 (UT), with reducer, taken with ASI 120mm

Only a very thin filament could be seen.

I've fully enhanced my Nexstar mount so that now it has a longer controller cable, no more shake induced by the short coiled cable!  Also, I've added three very large rubber padding to reduce the vibration and they're oversized for better stability.


Saturday, September 22, 2018

20180921 Observation with Almy

I pulled out my 85ED when I saw the Mars and the moon hanging outside my windows.

I looked at the Mars with my 4mm TMB, and then I turned to the moon.

Took a couple of images, and then I called my younger daughter Almy me.  She enjoys the view through the eyepiece and she even took some afocal snapshots with her mobile phone.

All the images below were taken with my ASI 120mc, yes I was too lazy to switch back to the 120mm after imaging the Mars.

1538 (UT), processed with drizzle 1.5x:-


It is getting farther away and thus smaller...

1542 (UT):-



1543 (UT):-


1545 (UT):-

Monday, September 03, 2018

20180902 Mars


1554, (UT), 85ED with 5x Powermate Drizzle 1.5x, ASI 120mm.

It was amber rainstorm this morning, but it's quite clear tonight.  Seeing very poor and I could see a shaky image even at very low power.

The Martian dust storm seems cleared up, maybe the best image taken this apparition for me.

I has been fine tuning my Nexstar mount, a circular wooden base was added for better balance, preventing tip over.  The controller cable was made longer so that the shake from the cable won't induce vibration to the mount now.  The base was still unstable, and I placed an eyepiece cover below to stop the vibration, since I've only four small pads below.  Some more would be added shortly.


Thursday, August 02, 2018

20180802 Saturn visual observation

I found that I could observe the Saturn from inside my home this season, so I tried again last night.

Saturn was there, but the sky was very bad, poor transparency and seeing.  Therefore, I dare not to pull out my ASI for imaging.

Instead, I called my daughters in and show them the eyepiece view.

I found that the 20mm widescan is not too easy to view through.

After very brief observation, I put the new 30mm ES 82 degrees in, and then let it go.  We went for PUBG again.  And after maybe around 30 minutes, Saturn was still in the field for a one-star alignment, not bad, right?


Wednesday, August 01, 2018

20180731 New Eyepiece 30mm ES 82 degree and Saturn

Since I got a 2" focuser for my Ranger, I always wanted to go for a 2" diagonal plus a wide field grenade level eyepiece.  Formerly, I had owned an Antares 2" SCT diagonal and also later a Zhi-tong 2" diagonal, and they served me well, and my eyepiece was a 2" 40mm Pentax SMC XL which I loved so much!  I sold it before I transformed my Ranger into 2".  I always missed the wide field and the observation comfort of the Pentax SMC XL!

Recently, I got my 85ED and it features a 2.5" focuser.  My Tele Vue 1.25" diagonal is aging after twenty years of service.  So, it's time to update myself with a modern 99%+ dielectric diagonal, so why not go for a 2 incher?  It's a ES carbon fibre model which I've written about it shortly before.

After about one week of usage, I'm confident about the brand.  So, I took the plunge to buy a 30mm 82 degree eyepiece of the same brand:


It feels heavier than the Pentax SMC XL, a little bit bigger as well.  It's very well made, despite it's made in China.

First of all, I tested it with my 85ED on terrestrial objects and it's color free.  It is not as comfortable as the Pentax SMC XL but it's close.  The eye-relief is decent, the eye cup is small but effective.  I could see the whole gigantic 82 degrees field of view all at once, the feeling is immersing.  With the Pentax SMC XL, the feeling is huge and wide, and this one, there is more space than you can view all at once.  The higher magnification should be favorable.  Remember, I had sold my Pentax SMC XL and so it is not a side-by-side comparison, but it's a comparison from my highly favorable memory of the Pentax.  So, it could be unfair.

Switching to the sky, stars were pinpoint to about 80% of the whole field and the outer stars require re-focusing to become pinpoints, and thus it's field curvature.  I don't know it's the 85ED or the eyepiece itself.  But anyway, it's good enough for all purpose.

With the 85ED, it's at 17x having a 4.82 degree true field of view!  It's just stunning!


With this eyepiece, re-balancing is a must!  I took the above picture before the test.

I scanned around the little patch of sky from inside my home, and I found a strange "star", I soon realized that it must be Saturn.  Plugging in my 20mm widescan eyepiece confirms that.  Hey, why not take a snapshot of it?


1607 (UT+8), 85ED 5x Powermate, Drizzle 1.5x.

Poor seeing at 5/10, transparency 5/10.  Saturn is a rare target for me, I want to try more this season when it's still in good position from inside my home.

My setup was changed a bit last night, I order two more short monopod extenders for my Nexstar mount, I used them to replace my camping table, which is not very stable after all.


It's now more stable, but I will want to make a wider base for it, to prevent it from tipping over.  I will also want to make a longer cable for my Nexstar controller so that I won't introduce vibration to the setup when I need to touch the keys.


Saturday, July 28, 2018

20180728 Mars Opposition + Total Lunar Eclipse

Mars Opposition could be observed for a period of time, say a week or even a whole month.

Therefore, the total lunar eclipse was the prime target earlier this morning, it's the longest total lunar eclipse for the century.  I came home after working and slept nearly immediately to prepare myself to wake up for this event.

The sky was not promising, one word says it all: misty.  When I woke up after less than two hour of sleep, it didn't improve a bit... luckily, the moon and the bright Mars were still visible through the mist or thin cloud.

Encouraged, I pulled out my 85ED and mounted it on my Nexstar mount, in the hope to capture some high power shots with my ASI 120mc.

Took two clips but none of them was stackable, so I posted the raw video as below.  The exposure and gain were both very high, yielding very low frame rate:




Since the mount was occupied, I took this with a Canon 100-400mm hand-held using spot metering, 0246 (GMT+8):


And then a wide field shot, 0248 (GMT+8):


Manual exposure was used to keep the exposure fast enough not to overexpose the lunar disc too much.

And then this one at 0318 (GMT+8):-


And a quick closer up 0323 (GMT+8), to show the red hue:-


And then things got worse, I have to use GOTO to the moon!  Can you see the moon in this shot?  I am sure not!  The shot below also told you how close the moon to a nearby new building.


But you know, when there's nothing, there's really nothing there!  I pulled out my 10x30 and checked with my eyes, nothing.  5 seconds exposure?  nothing.

When you were about the give up, I realized that I could just close the window and sit in an air conditioned room to wait, so why not?  After some wait and hey... was it a cloud or what?  no, it's the moon!  taken at 0409 (GMT+8) 


The Mars was way brighter than the moon by then, not unexpected, right?

04:22 (GMT+8), probably the best eclipse shot of the night, stars could be seen around the moon, clearest moment of the night.  I could imagine such a totality would be wonderful under a dark cloudless night!  But hey, we could only imagine as a Hong Kong observer!



04:25 (GMT+8), and the Canon 100-400mm got the mount now, I checked the EXIF and it was at 200mm, a zoom lens could be nice for this purpose, you could frame your shot the way you liked:-


And a shorter exposure one at 0426 (GMT+8):-


I tried to get a close up but it was shaky, since the cloud was getting thick resulting in longer exposure.  The cloud window was closed.

Alright, time to sleep.  Luckily, it was Saturday in the next morning so I could sleep longer to make up the observation time.

Finally, a few slash back shots:

First up were two mobile phone shots while going home, before the eclipse:


This shot with a historical building in the front, should be taken as layers and merged back, but I got no time to do so.


Equipment shots, of course, taken during cloud cover, just a record.  The new ES diagonal is nice.




And finally, the Canon 100-400mm lens on the Nexstar:


Sorry that I (very rarely these years) bought new equipment these weeks, and still got some in transit, weather curse applied.

A short summary in Chinese: 香港天文,注定有雲 (Hong Kong astronomy, cloudy astronomy)