20260414 Comet 2025 R3 Hunting

Woke up at around 5:00am without alarm, pulled out the S30.

The sky is getting some twilights, low in the horizon, scanned with my Canon 10x30 IS but not much luck.  I have no star chart but just scan around near the horizon.

The S30 is struggling too.  The first frame was captured when it says horizontal calibration failed.  It was all white, the twilight was there already.  I should reduce the exposure after it settles with its initialisations and autofusing.

Time is running out, no chance to lower the exposure.

Mission failed, temperature close to zero wthout wind.

Call an end at 5:28am.

20250413 Testing the reincarnated Canon FD 300mm f2.8

It can reach focus!  Autofocus works perfectly.

The testing target is M81 and M82, 180s exposure unguided, very fine subexposure.

And then switch to M13 for another test shot, 30s subexposure unguided.

M101 for 180s subexposure.

Setup the S30 along at 22:00, starting from M49, but then that part of the sky was not clear enough.

Goto M84 and M86, will probably spend quite some time tonight on these.

And then M87.

And then M89, M90, M58 within the same frame:

20260412 M13 late night

Just back from Manchester and saw a great sky along the way back home.

Setup the S30 and point it at M13 from around 23:33, let see how much photon I could get.  18 minutes finally.

Then M64 for a short period of time, 21 minutes finally:

Well worth to re-visit it later.

Too bad that I don't have chance to test the 300mm f2.8 out tonight!

Transforming the Canon FD 300mm f2.8L into a telegraph with autofocus via JMI NGF-CM plus a ZWO EAF

The first attempt does not work out well, since it's difficult to print the 77mm thread.  

I have tuned the printing parameters for several times but it didn't help much.

Therefore, I design another adapter from ground zero again.  I found the original 77mm ring for the FD mounting mechanism could be reused and here's the prototype:

Some fitting issues, and I did the fitting with a cutter.

It looks great, with the NGF-CM fitted.

The whole model was refined and printed again.  I will use black PETG in the final version and add felt lined black sticked inside.

Three generation of equipments combined: Canon FD lens, JMI focuser and ZWO EAF.

I am so excited, and I hope I can try it out soon.

--

Prototypes

Those thinner rings were the attempts of printing 77mm threads.

The bigger blue adapter was the first prototype of the redesigned adapter without the need of 77mm threads.

Summary: 3D printing could not be too precise, they are plastic afterall.  Expansion and contraction, annealing is apparently an issue.  They are pretty strong but to maintain accurate precision and collimation, you will need to redesign the whole thing.  Don't even try to push its precision or strength, try to avoid these.

--

20260409 Additional Notes

Set the limit of focuser travel of the NGF-CM with ZWO EAF in my ASIAir last night.

Set the focuser position to the middle of the travel.

Confirmed that it could reach infinity focus with ample of rooms for adjustment, even without touching the NGF-CM.  So autofocus should work, but to be verified with the stars.

20260406 M102 et al

Continue my Messier Marathon with suboptimal sky.

Started at 9:23pm, summer time marks the beginning of less imaging time.

First up is M102, 28 minutes of exposure:

Next up is M105 with M95 and M96 (mosaic), will do at least one hour of exposure, finally 65 minutes of exposure:

Below will be left for the next time: M103, M85, M64.

Also setup my Canon 200mm f2.8 with guiding Markarian's Chain, containing M84, M86, and surrounding objects, etc.  

No polar alignment was done, just very rough focusing since my ipad air was dead.  Not really easy to do all these with a small mobile screen.  

Try to stack 30s exposures like the S30 therefore.

Very poor result.

Second attempt, reduce exposure to 10s and then stack.

20260405 M109 and Messier Marathon

The quest continue...

Started at 21:42 rather late but it cleared up a bit after the storm dave.

I will send the whole observation session with it, maybe around 45 minutes.  A promising target which deserves better treatment.

Finally, 1:7:30.

20260329 Clear with showers, occassional stormy

Started at around 9:33p (summer time started)

First target is M44 which is pretty close to the moon, but open clusters should be fine.  

6.5 minutes exposure

M63 for 12.5 minutes

M94 for 16 minutes:

M3 for 18 minutes.

Stopped eventually due to shower.

20260328 Messier marathon session three: thin Cloud Observation

Start at around 9:50pm.

M101 is the first target, I have very limited time tonight but I don't want to rush like the last time.  So I am spending more time on this target, 47.5 minutes.

M106 is the next and the last target, see if 10-15 minutes would be good enough.  Stopped at 13 minutes, time to sleep, there's one less hour tonight due to switching to summer time.

20260327 Messier marathon session two: clear Skies with sudden rains

I still too the plunge to continue my Messier marathon.

The first target is M45 before it's sinking too low, I expect to spend 20 minutes with it for a 1.3x mosaic.  Starting from around 20:40. 

It refuses to perform AI denoise at 20 minutes, saying that the mosaic is incomplete.  I shall wait a little bit longer, maybe until 25 minutes.  So sad further exposure ruined the stacked image, I didn't save any individual and so it's really less than useable.  Just a record, 25 minutes wasted.

Broken M45 mosaic:

I hope to do one more two more objects before closing.

M100 is the next one, really low.  Let me do 8 minutes or so.

And then M98 with M99 before they sink too low (also with NGC 4208 plus NGC 4237), let me do around 8 minutes or so.

Then M67 for 5 minutes.

Finally M65 + M66 and also NGC 3628 before it snows (forecast), so for 30 minutes.   Got only 13 minutes before cloud rolling in.

Not a bad night, the forecast was bad but I got a handful of targets done.

Canon FD 300mm f2.8L second generation

With my new 3D printer, and the help of my daughter who is keen on making 3D models, this project is realised so quickly and it's a BIG success.

It was pessimistic about the thread (77mm 0.75 tpi) but it turns out to be nearly perfect.

It can reach infinity focus with some rooms.  So now this little lens could do autofocusing with asiair!

Aside from using an eyepiece, I also use 533mc pro to test.  It works without problem.

Other than the above adapter, I will be making two more:

a. 2" nosepiece in order to be used with my 85mm refractor for fine focusing

b. SCT female thread in order to be used with my SCT

I can then sell that CYCK focuser.

--

I have removed the ebay ad of my Canon 300mm, will be keeping it and making good use of it.

I have ordered black PETG carbon fibre filaments to print a strong adapter.  My daughter has modified the adapter to have more threads on more secure connection to the lens.

--

Later I found that the thread is less than perfect so that it's not screwed all the way in and thus leaving the gap.  It is probably not strong enough.  But the good news is that, if the quality of the thread improves, I will get even more room for focusing.

Time to do some fine tuning.

--

I have printed a new version with PETG, stronger apparantly.  But yet, the thread is less than perfect.  I will need to do some more experiments.  

I have printed another ring only to save filament and time.  But then it still less than perfection.  

JMI NGF-CM with ZWO EAF

Since the JMII NGF-CM is lower profile, I want to see if it could be used with the Canon FD 300mm f2.8L.

It might be able to replace the CYCK focuser entirely, to use with my Ranger like now, to use with my 8" SCT, and to use with my 85mm refractor for deep sky imaging.

The first feasibility test was to attach the ZWO EAF to the JMI focuser, to replace the existing JMI mini DC motor.

Original JMI mini DC motor removed.

Replace the coupler on the focuser shaft.  It was for the DRO controller which I had sold.  Now it's attached to a coupler bundled with the ZWO EAF.

Next step is to attach the focusing motor, and I have proper screws on hand fortunately.

The next test would be to try it out on the Canon FD 300mm f2.8L to see if it could reach infinity focus.  If that could be done, I am going to keep the lens.  I now had it posted on ebay but so far no one really placed a bid yet.

I did a handheld test and it works with a 20mm eyepiece.  Since the 533mc could take a 2" nosepiece, and thus saving 1cm from the 2" to 1.25" adapter!  This makes even more room for reaching infinity focus.

Specification of the adapter: everything like my existing Ranger adapter, except it's with 77mm female thread instead of 76mm.

The project looks quite promising.

I will certainly keep my Canon FD 300mm f2.8L if that could be done.  I will then be able to have autofocusing with this lens!  My 533mc has a relatively small sensor which works pretty well with this ancient lens.

Next step is to make a SCT adapter for the JMI-CM, and then a 2" nosepiece.  The CYCK focuser could then be sold!

--

I believe one with a 2" nosepiece would be good enough.  

I have a 2" adapter on my SCT so it's good enough.

I can put the whole thing into the focuser of my 85mm refractor too.

20260325 M51 by Seestar S30

I should create a new entry for this M51.  

I got 1 hr 40 minutes of exposure:

Processed by the box, nothing else.

Surprise to see how this little Seestar S30 could do.

Glad to have a partially clear night suddenly.

20260325 Seestar S30 Messier marathon: Session one

Partially cloudy (maybe 2-3/10) sky, bright moon

Last time should be session zero, since this was the session I got the idea about a messier marathon.

So this is session one, I am going to capture a few open clusters.  Mainly a filling session, to catch some targets before it's getting too low or disappearing soon.

My first target is M36.  It is pretty close to the moon.  So I didn't spend much time with it, so 5 minutes first.  Less than optimal, will come back later if I have time.

My second target is M37.  Even closer to the moon.  Again, 5 minutes.  Less than optimal, will come back later.

My third target is M38 with NGC 1907, also close to the moon.  Again, 5 minutes.  Less than optimal and come back later.

Next one is M34, this is farther away from the moon.  But since it's just an open cluster, I spend 9 minutes on it.

Switching to M51 finally, one of the best targets of the tonight recommended by Seestar.  I will give it the rest of the observation time tonight.  At least 30 minutes, the one below was around 35 minutes:

Finally, accumulated for one hours of exposure.

Going from target to target quickly tonight, this is the feeling of running a marathon.

The sky is getting clearer, but it's time to sleep.

When the mini-observatory box is done, I could then leave the setup alone.

Seestar S30 Messier Marathon Log

Those marked with a (-) is less than optimal.

M1 2025/12/16

M3 2026/03/29 (*)

M13 2026/4/12 (*)

M15 2025/12/8

M27 2025/12/4

M31 2025/11/21

M32 2025/11/21

M33 2025/12/20

M34 2026/3/25

M35 2025/12/8

M36 (-) 2026/3/25

M37 (-) 2026/3/25

M38 (-) 2026/3/25

M42 2025/12/13

M43 2025/12/13

M44 (-) 2026/03/29

M45 (-) 2026/3/27

M51 2026/3/25 (*)

M58 2026/4/13 (-)

M63 (-) 2026/03/29

M64 2026/4/12

M65 2026/3/27 (*)

M66 2026/3/27 (*)

M67 (-) 2026/3/27

M74 (-) 2026/1/3 (*)

M76 2026/1/4

M81 2026/3/20 2026/3/6 2026/12/16 (*)

M82 2026/3/20 2026/3/6 2026/12/16 (*)

M84 2026/4/13 (-)

M86 2026/4/13 (-)

M87 2026/4/13 (-)

M89 2026/4/13 (-)

M90 2026/4/13 (-)

M94 (-) 2026/03/29

M95 2026/4/6

M96 2026/4/6

M97 2026/3/21 

M98 (-) 2026/3/27

M99 (-) 2026/3/27

M100 (-) 2026/3/27

M101 2026/3/28 (*)

M102 2026/4/6

M105 2026/4/6

M106 2026/3/28

M108 2026/3/21 

M109 2026/4/5

(-) is suboptimal

(*) means worth trying again 

--

20260329

It's good to push myself to capture something even in the worst situation.

It's nice to get some ideas about the size, the location and the magnitude of more targets.

New equipment - the joy of visual observation

It's a reclining chair.  

Observation with my Canon IS is just fantastic!  Now, I just want darker sky.

My neighbour keeps his light on all the night, and there is also a nearby street lamp.  

Nevertheless, scanning with binoculars are simply irreplacable experience.

 

20260321 Not so good sky - M108 Seestar S30

The sky is not very clear.  I will be using the SeeStar only tonight.

The target will be M108.  

M97 The Owl Nebula was captured accidentally on the bottom right corner.

I suddenly got a thought about running a Messier Marathon myself with the S30?

--

Equipment thoughts:

I will not upgrade my mount, since I won't use the 8" SCT for deep sky imaging.  

For planet imaging, my HEM15 will work with the 8" SCT.  

For deep sky observation, even my SVBony SV225 will work.  So, it's a keeper.

Maybe just sell that f/6.3 reducer and then done.

20260320 Jupiter and M81/M82/NGC3077/NGC2076

Setup the S30 for mosaic around M81, M82, NGC3077 and NGC2076.

1:37 hr of signal acquired.

One with latest AI denoise another is raw stacked.

Trying out Jupiter with my 8" SCT, collimation was off after quite some time.  

Some videos were taken at prime focus, I didn't take any after inserting the barlows.  Collimation was pretty off.

(result pending)

Focusing with the short pier is no fun at all, centering the Jupiter was not too difficult with the bigger sensor of the 533mc but I don't think it's much fun.  I am one more step closer to sell it, for visual observation a dobsonian might be better.  I don't quite like planet imaging any more.  Long focal length deep sky would require a better mount which I won't probably want.  Time to downsize?

--

20260321 Followup

The collimation screws were too long, it should be 8mm but mine were 12mm, maybe that's why they couldn't hold the collimation well enough.  Order has been placed to get 10mm collimation screws since I could get exactly 8mm.  The new one has thinner thumb holder was shorter, the lens cap might be placed on after changing?

On checking my blog, I was considering adapting the NGF-CM to the ZWO EAF.  It's well worth further exploration.

Mini Observatory Project based on SeeStar S30

A small garden storage box will be used with the following dimension:

56cm * 41cm base and it is 50cm tall.

A rigid solar panel will be placed on top of it, with the following dimension:

101cm * 46cm.

It will be used to charge an old car battery.  

The battery will make the whole thing more stable, and will not be blown away easily by wind.  The SeeStar S30 will be placed on top of the battery, making it close to the cover for unblocked view.

The battery will be providing power to the SeeStar S30, as well as some minimum lighting and maybe a small ventilation fan to keep moisture out.

Will try to add mechanism to close automatically when rain is detected.  

Automatic openning is optional.

--

20260319 Update

The storage box arrived and it's of good size.  

Strong and waterproof enough as it looks.

The solar panel is probably too big and heavy, I will need to find something else.

--

20260320 Update

Maybe the new solar panel should be placed on top of the storage shed, the exisitng flexible panel should be moved in the front.  This combination should provide far more than enough power except winter.  I shall then use the power station more now, maybe find a way to mount a powerful kitchen ceiling lamp to save energy in the long run.

My LiFePO4 will be charged via the power station.

The older flexible panels will be installed on top of the mini-observatory, to charge a car battery continuously.   This battery will be used for charging up powerbank for the S30, as well as to power fan and some backyard light?  

--

Solar panel installed:

Drill another hole on the side to let the wire goes inside:

Placed the battery and solar controller inside, need to find a way to "fix" it in a better location.  

Door closed, looked quite nice!

These two panels are relatively old.  One of them were damaged partially and the power output is reduced.  Anyway, just collect as much as sunshine as it could.  I have power banks which could be charged fully by the power station easily.

Need to find way to mount the new solar panel on top of the storage shed.

20260307 Canon 200mm f2.8 NGC 2174 Monkey Head Nebula + IC443 Jellyfish Nebula

I went back to my Canon EF 200mm f2.8 after testing my Canon FD 300mm f2.8.

I have used a Optolong Quad Band light pollution filtyer this time.  I am trying to compare it with the Antlia Quad Band.  Preliminary ideas:

1. the Antlia Quad Band should have tighter passband, you can see if even side by side, simply less light could pass through it

2. bloating stars are a side effect of (1), and thus the Optolong Quad Band gives less bloating bright stars as a result

On setting the things up, I found that I failed to focus my 200mm lens for unknown reason.  

In order to save valuable observation time, I went to use the Guidescope with the guiding camera for polar alignment.  I even used this combination to take images of the M45, the result was quite unexpected.  Seems like a monochromatic camera has a clear edge, despite it is not a cooled camera. 

60s expoure, 11 frames in total, taken with ASI462mm and the guidescope of 230mm focal length:

I aimed at M45 since I know there will be some bright stars for focusing.  Later, I found that the lens cap was not removed.  <GRIN>

Finally, I turned to NGC 2174 and IC443 for the rest of the night.  Quite busy area in the sky, quite of subexposure was affected by satellites.  Total two hours of exposure.

I then pulled out my S30 again, this time pointing at IC434 the horse head nebula.  Exposure of slightly more than an hour, pretty low in the sky, in the direction of a street light.  Field rotation pretty serious in that part of the sky.

It's never in a good position in the UK.

20260306 Equipment Testing: Canon FD300mm f2.8 on the double cluster + Seestar S30 in EQ mode

Canon FD300 f2.8 Testing:  Other than the double clusters, I have tried a number of other targets as well.  They will be used to demonstrate the lens.

EQ mode testing failed, since the Seestar failed to point at a clear patch of sky when doing the polar alignment.  It keeps resetting its WIFI for unknown reason.  I have given up and pointed it to M81 and M82 for the rest of the night.

1.5hr in total, altazimuth mode 30s subexposures.

My daughter came back and I setup my 85mm refractor on a SVBony SV225 mount for some visual observation.  I have used my Canon 10x30 IS as well.  Very fine session.

I tested a new zoom eyepiece which is better than expected.