My new 85ED refractor

It has been a long time since I bought a brand new telescope.

My brand new telescopes include my first scope Celestron C90, and then a Tele Vue Ranger.  Later a C8 and then everything else was second hand, including a Takahashi Sky90, a couple of C5, ETX 60, PST, a 5 inch Maksutov, etc.

This time I got a 85mm ED refractor.  The Tele Vue Ranger is really out dated in terms of its lens, don't get me wrong, it's a perfect achromatic refractor but that's all.  For H-alpha solar observation, it still performs exceptionally well because it's well figured.  For monochromatic light, it's unbeatable even compare with modern day FPL-51 or even FPL-53 based refractors!

Okay, let's go straight to this little new guy:

The core is its objective, it's a 85mm lens at f/6 with focal length of 510mm.  Very close to my Ranger which is 480mm.  This guy is actually a bit faster.  At f/6, even a FPL-53 based refractor would be hard to be a real apochromatic, not to say this is just a FCD1 based (similar to FPL-51) one.  This scope was advertised to have FCD1 matched with H-TF3L, but whether H-TF3L is special enough apart from a simple flint, I don't know.

The scope looks very nice.  It comes with a rack and pinion focuser, with dual speed knobs.  Focusing is smooth.  It's a 2.5" focuser and it comes with 2" and 1.25" adapter with compression ring.   The focuser is rotatable.

The tube rings are very nicely machined.  The including dovetail is a bit too short, I've replaced it with my Intes and it's just about right length for better balancing.

And worst yet, the original dovetail is too short to fit in my Nexstar mount.  Even a long camera tripod balance plate works better, as shown below.  Notice that if the dovetail is shorter than the clamp saddle, it simply won't fit in:

I've checked the tube and there is no light baffle inside, just like the Ranger with dull black sand finish, not bad and it keep its weight low.

The paint job is not very good, there are some missing paints here and there.

The dew shield is retractable, so that at its minimum, and it's about the length of my Ranger.  Very portable indeed, and I've enough room inside my dry box.  Of course, this guy is heavier, nearly 1.5X of the Ranger.

And the tube rings:-

with the Intes dovetail, the original one should be lighter.

I've removed the left focusing knob and replaced it with a brass gear, and I handheld a small DC geared motor there and they mesh well.  I shall make mounting hardware for it asap.  I deadly want motorized focusing as always.

Enough modification for the first day, em?

Guess what, I'm lucky enough to take a test shot with Jupiter during the first night!  It's less than 3 hours after its arrival.  Seeing was very poor but then at least I can tell, the chromatic aberration is far better than my Ranger, at half the cost twenty years ago!  When inflation is taken into account, I get a very nice deal indeed!  I hope this is going to be my work horse for planet and general observations.

I will keep my Ranger solely for solar works, and I believe the Ranger might still be better than this new refractor in terms of monochromatic solar imaging.

Due to the fact that I already had my Canon FD 300mm f2.8, it makes not much sense for my to buy the field flattener for this scope.  The next step might be a 2" diagonal plus a 2" wide field eyepiece, but then I shall be using my Canon 18x50 instead?  Let's wait and see, there's no need to rush.

Maybe motorizing the focuser and attaching a Rigel Quick Finder are among the first priority.

20180710 Jupiter and a new telescope

I sold all my telescopes except my Tele Vue Ranger.  But then I wanted to look at the planets and I soon realized that the chromatic aberration is annoying.  I don't need aperture, and I need to keep portability so a better refractor is a normal step forward.

I didn't buy a new telescope for a long time.  I did buy some 2nd hand telescopes, and an absolute new one might be my C8?  This time, I bought a FCD-100 based ED refractor.  Let's see an image taken tonight first:

1342 (UT), taken with a 5x Powermate, we have the GRS on the lower left.  I'm pretty confident that this little new refractor is going to perform quite well.

Seeing was extremely poor, and cloud was floating around.  I got a single AVI after waiting for a long time.

A separate article will be written on the first night impression of this refractor, at less than half the cost of the Ranger twenty years ago!

20180706 Jupiter (missed the shadow transit)

I didn't do this kind of shots for many years, maybe like 10 years!

Too bad that cloud rolled in, and I missed the shadow transit!

A small telescope could bring much fun, I shall keep on!

Conclusion about the Canon FD 300mm f2.8

The conversion is very easy, and could be done with off the shelf parts, and such conversion could be easily reversible.

When a 2x barlows is inserted before the diagonal, it could be used visually with an eyepiece.  It is not bad as a wide field telescope.

However, high power performance suffers especially with bright objects.  It is because it is a telephoto lens, so the flare and internal reflection renders it useless.

I've tried every effort to remove the internal reflection but in vain.  The problem must be in the unmodified part of the optical chain.  On looking at the inside through the objective, I believe that the internal unblackened parts could be the source, but I've no way to verify.  The protective element before the flourite lens could be another source as well... but again, I've no way to verify.

So this lens will be reserved solely for imaging purpose.  It is still a very nice 300mm f2.8 astrograph, it's very compact, light weight and thus highly portable.  It's also very well corrected.

20180627 Jupiter

Imaging time again!  Same setting as yesterday:

1441 UT.

20180626 Jupiter

1438 (UT), Ranger with 5x barlows, 1.5x Drizzle in AutoStakkert.

RGB aligned by Registax and color balance too.

Poor seeing, exposure reduced by pushing gain, giving higher frame rate.

20180611 Sun (closing this season)

I waited until very late 0741 UT or 1541 local time, but the sunshine didn't come fully inside my home.  So, most of the aperture was blocked, very poor resolution with uneven illumination.

Closing this season, therefore.

20180610 Jupiter

Processed by AutoStakkert 3 with Drizzle 1.5x, Ranger with 5x Powermate, ASI 120mc

1522 (UT).

I pulled out the camera and looked through a 4mm eyepiece, terrible high frequency seeing. 

70mm aperture is not bad in this case.

20180605 Jupiter

It has been a long time since I took image of Jupiter.

First two taken at 1550 (UT) with a ASI 120mm, first one processed by AutoStakkert 2 and the second one with AutoStakkert 3 with Drizzle 1.5x... I also carefully processed it further to enhance the contrast.

Next one taken at 1553 (UT) with a ASI 120mm, processed by AutoStakkert 3 with Drizzle 1.5x... I also carefully processed it further to enhance the contrast.

Last two taken at 1555 (UT) with a ASI 120mm, first one processed by AutoStakkert 2 and the second one with AutoStakkert 3 with Drizzle 1.5x... I also carefully processed it further to enhance the contrast.

I believe AutoStakkert 3 is better and I will use it afterward.

20180524 Moon

Moon again, with my Ranger and 5x... today on top of my new camping table.

Of course, not very stable but imaging is possible.

Using two of my favorite craters as target.

1259 (UT):-

1301 (UT):-

Quite nice, fit my small window platform very well!

I will probably bring this small table out for observation if I were to use my Nexstar mount.

20180523 Moon

It has been sunny and extremely hot for a couple of days, I even pulled out my Canon 18x50 IS to go for a short casual observation in a nearby light polluted playground but then the sky was filled with thin cloud by then.

Tonight it seems quite clear, and I pulled out my Canon FD 300mm f2.8 to do some high power shots, but all the processed images show internal reflection, so this lens leaves me no hope for high resolution imaging.

I've tried to stack two 2x, and different combinations with a Tele Vue 5x:

Then, I pulled out my 20 years old Ranger and took these two shows with my Tele Vue 5x Powermate:

1420 (UT)

1426 (UT)

20180520 Sun

Summer came, and the direction of the sun inside my room is no good.

Seeing 3/10, transparency 7/10 - nearly the best we can get here in Hong Kong.

0642 (UT), exposure optimized for surface detail, prominence was pushed by post-processing.

0644 (UT), exposure pushed up to show the prominence.

Relatively lack of surface detail, some nice prominence around the edge.

By poor viewing angle, there is only around half of the aperture was illuminated.

20180501 Sun

We had a holiday today, it looks hot and shinny outside.  But when you turn your scope to the sun, you saw the moving thin cloud.

Captured a short clip on the relatively featureless solar disc, both AS!2 and Registax failed to come up with a stacked image... 

Just a record.

--

On placing the stuff back, I found these cheapy 18650 works very well for powering my setup.  I did 2-3 times per month on solar imaging, and I only charged them once, not because it ran out of juice, but just I want avoid them to flat out completely.

I've sold my C5, that GOTO Mark-X, and the long time partner Gitzo G106.  My equipments dropped to a minimum.

20180409 Sun

0557 (UT), yet another record during my day off.  Cloud moving around, but not too thick.

20180408 Sun

After the cold front, seeing stabilized but then the solar surface is still quiet.

I pulled out my dark cube in the hope to try it again with my new faster laptop, but then Sharpcap hangs whenever I tried to capture an AVI.  Need to figure out why, and to solve it.

Captured by ASI 120mm, 0618 (UT).

The sun is now in a strange angle from inside my home, I anticipate that I will not be able to do solar imaging after one month or so.  Will need to wait until winter again?

DIY focusing motor controller enhanced version

The first version is made with a junk 18650 power bank, I've to remove the original USB socket and the charging circuit so as to accommodate the buttons.  Once the 18650 ran out of charge, I have to pull it out for recharge which is inconvenient.

Later I found that there is a dual 18650 version available at very cheap price without battery, so I ordered them and carry on the modification.  The idea is to keep the power bank circuit and I will only use a single 18650, so the space left could be used for the buttons.

Once the 18650 ran out of juice, I can recharge it with a standard USB cable.  This controller could serve as a emergency power bank as well.

The whole thing costs less than $3 USD, most of the parts were recycled parts.

--

Tonight, when I was clearing up my messy equipment cabinet, I found that I have a motorized DEC for my Sky Adventurer and it requires a socket to control.  I used to have another controller for it, but why not consolidate them as one?

Here we go, it only means some more drilling, fitting and soldering work.

So, let's test it with the DEC motor of the Sky Adventurer:

And then go back to the focuser of my NGF for my Ranger:

I even tested to use this controller for its original purpose, i.e. a power bank.... and it works flawlessly despite it only has a single 18650 rather than two.   The blue LED lit up for this mode.  On charging from the micro USB, the red LED lit up as it should be. 

Very nice one, way better than my original one.  More powerful, compact and more beautiful.

Equipment updates

Just sold a number of stuff which I rarely use:

1. GOTO Mark-X
2. Celestron C5
3. Gitzo G106
4. Manfrotto 410

My major equipment after selling the above:

1. Solarmax 60 with BF10
2. Tele Vue Ranger with NGF-S
3. Velbon tripod
4. Nexstar mount
5. Sky Adventurer mount
6. Polemaster
7. ASI 120mm and 120mc
8. Canon 10x30 IS
9. Canon 18x50 IS
10. Canon FD 300mm f2.8 modified to EF mount

Time to tidy up my equipment cabinet and the dry box.

The equipment which I use most is the Solarmax 60 Ranger combo on Nexstar mount for solar imaging indoor.  Next will be the Canon IS binoculars for casual observation during camping, or overseas trips.

Less usage will be the Sky Adventurer mount for wide field or deep sky imaging with my Canon DSLR.  So this equipment lineup is about right for me.

20180312 Sun

The cold front is weakening, and the temperature is getting up.  Moderate seeing at 5/10 and transparency dropped, I would say 4/10.

Featureless solar disc, an active region might form at the lower part of the solar disc?

0620 (UT).

20180309 Sun

A cold front came last night and temperature dropped sharply, windy and poor seeing.

0713 (UT), Ranger with reducer, Solarmax 60 + BF10, ASI 120mm

20180305 0559 (UT) Sun in H-alpha

It's a cloudy day, feels like summer in terms of temperature, humidity and the sky condition.



Due to the amount of cloud, I would rather upload the video clip rather than to stack the frames.  Just to let me glimpse the surface features.

20180131 Total Lunar Eclipse (Blue Moon)

We have a blue moon tonight, and we have a total lunar eclipse at the same time.

Taken at 9:26pm (GMT+8)

And another one at 9:34pm (GMT+8)

Cloud moving around, we hardly got some small gaps for imaging.

I only got a simple tripod:

It was really cold and windy, and the feeling was great.  If I had more time, I will probably be using a tracking mount plus a higher power setup.  And also my Canon 18x50 IS, too!  Anyway, it's good enough to have some fun. 

20180118 Sun, tweaking parameters of ASI 120mm

Seeing rather bad at 3/10, transparency very low with pollutant at 3/10.

Got some more time to tweak the settings of the ASI 120mm camera.  I never really studied enough for this little camera, today I switched on the high speed mode, and adjusted Turbo USB to 100 and I finally got more than 30 fps!  Silly me.

I should have adjusted the gain but I forgot what values did I set.

The first one was taken with my usual setting, at slower frame rate, taken at 0703 (UT).

After tweaking, taken at 0710 (UT) at more than 30 fps (around 32-34 fps), and gain lowered.

I found the contrast slightly better, less noise, etc.  The higher frame rate should freeze the seeing better.

Sharpcap kept the record rather well, gain was reduced from 50 to 40... I believe it could be driven down a bit further.

20180111 Sun

Day off today and the cold front is still passing, and it turns sunny today.

Poor seeing is expected and thus no fine detail could be resolved, taken at 0639 UT.

There are a few dim filaments around, with an interesting on on top right hand corner, which extends a bit into the dark space as a small hedgerow.

Too lazy to add false color to this relatively featureless one, just a record.

20171220 Sun

Got a short break today, took a snapshot under poor seeing.

0753 (UT)

20171211 Sun

Winter means poor transparency due to the wind from mainland, and it usually means poor seeing with sharp temperature changes.

0550 (UT), no fine detail could be seen.

0552 (UT), push up exposure to show the prominence.

20171208 Sun

Seeing no good again, temperature is dropping since yesterday night so it accounts for the poor seeing.  The solar disc is kind of featureless too.

0631 (UT)

20171204 Sun

0617 (UT), extremely poor seeing, dare not to further process after this stacked wavelett processed version.  Just a record.

20171117 Sun

Seeing bad, transparency 4/10.

0617 (UT), there might be a small active region forming at the right near the center, but the most interesting feature is the filament at the 3 O'clock position and it extends beyond the solar disc as a prominence.  Not very big, however.

20171109 Sun

Cloud moving around, the AVI was not stackable.

Only a very subtle filament available visually.

Just a record.

20171030 Moon

Same poor seeing, and even worst since it's even cloudy.  I've to wait until I can capture a few very short clips.

C5 with 2x barlows.

1418 and 1427 UT:-

Just for fun (no fun indeed)