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