Bad stars

[Baskevo]

Thanks James, that looks like exactly what I need. The trouble with AP is that, when something is a little off, it really gets to be a bother when you know it could be better. That's where I'm at right now. It really doesn't look that bad, but I know it could be better and it'll just keep bugging me.
I'm off to Highpoint to see about getting that t-ring. With any luck this will fix my problem.
John

I totally understand... I'm in the exact same boat. I just ordered my 4th Field Flattener, to see if I can get my curvature down a little bit more. Good luck!

Also, you might want to add some spacers to your order, because it doesn't look like it's totally off the mark in your picture. My guess is you are about +1 or 2mm from where you want it. I would add a set of 5, 10, 15, and 20mm with m42 threads. And seriously, CCD inspector makes it a lot easier when trying to figure out if things are getting better or worse.

[spectre]

Already have the spacers so that's not an issue. The t-ring being back ordered, that's an issue.
Patience is a virtue. It's always something.

[Baskevo]

I definitely understand that! I did a lot of waiting for things to not work with that Field Flattener

I decided to upgrade to the ES 80mm FCD100 and the HEX focuser... Hopefully that will be here on Monday! If the Field Flattener doesn't work well with this scope (which it probably won't), I might try the hotech one... I heard a lot of people have had success with that one.

[spectre]

Hi Baskevo, I have an update on my spacing issue. The thin t-ring arrived and we finally got some clear skies on the weekend so I can try it out.
Here is an image of M-44 from 2/22/2020 using the ES 102 CF triplet and my DSLR. 90 subs of 30 sec each, darks, flats, and bias applied. All processing in PI. I think I may have overcooked it but this was mainly to check out the stars in the corners. They look pretty round to me across the image. I still have color differences across each star, red on one side and blue on the other. Is there any way to correct this?
CC is welcome and appreciated

[Baskevo]

Those stars look great to me! I would be very happy with those stars!! I'm still not getting perfectly round stars... lol

As for the color, have you tried looking on a different monitor? Because the color looks great to me... I'm not seeing a difference other than what is usually natural!

[STEVE333]

Hi John - I got into this thread in Oct 2019 and just got back in today. I have the same ES ED102CF telescope and FF/FR from Stellarvue. I've always had the "rainbow stars" problem, but, thought it was the telescope. After following through this thread I just checked my FF/FR and there is no "55 mm" engraved on it anywhere. So, maybe that has been the problem all the time I've used it with the DSLR.

I now have a cooled camera, so, maybe I can achieve the required 45 mm. This thread has given me hope that the telescope is OK. I would be happy if my stars look as good as yours do now John with the new spacing. Hopefully this means my telescope is OK. That would be terrific!!!

Congratulations on persevering and solving a difficult problem.

Cheers,
Steve

[spectre]

Hi Steve, thanks for the congrats but I still have the rainbow stars, they 're just round now.
Any one have any suggestions about how to get rid of the 'rainbow effect'?
Hopefully thanks in advance
John

[STEVE333]

Hi Steve, thanks for the congrats but I still have the rainbow stars, they 're just round now.
Any one have any suggestions about how to get rid of the 'rainbow effect'?
Hopefully thanks in advance
John

John - Sorry to hear you still have the rainbow stars problem. The approach in the link below has helped me to reduce the amount of "rainbow" in the stars. In the Registration model box make sure to select Thin Plate Splines.

https://pixinsight.com/forum/index.php?topic=9536.0

Hope it works for you too.

Cheers,
Steve

[spectre]

Hi Steve, I clicked on the link but I don't see any attachments. I went to the Pixinsight forum directly and still no joy. Can you repost the information, I'd really like to give your method a try. Ideally, I'll be able to track down the underlying cause rather than fix it in post processing.

[STEVE333]

Hi John - I looked back through Flickr, but, the image (attachment) has been thrown away somewhere along the way. However, it just showed a magnified view of a portion of the image before/after the repair. You don't need it to try the repair yourself.

I hope you can find the underlying problem. I believe, with mine, that there is actually a some misalignment (decenter and/or tilt) of at least one of the triplet elements. It's the only thing that makes sense to me. I sent it back the Explore Scientific and they "adjusted" it. It was improved, but, still very noticable. It's so frustrating because some people with the same model are getting fantastic images with perfect stars!! Why me (and you)?

Cheers,
Steve

[Baskevo]

Why me?

Cheers,
Steve

I have asked that question a million times already lol I've gone through 3 scopes, 3 cameras, 5 field flatteners, and I'm expecting my 4th mount tomorrow! :sigh:

[JayTee]

James,

You are, by far, the most snake-bit guy I've come across since coming back to this hobby (which includes forum posting) full-time in 2012. Man, I hope things turn around for you soon. You absolutely deserve a break!

Expectantly,
JT

[STEVE333]

Why me?

Cheers,
Steve

I have asked that question a million times already lol I've gone through 3 scopes, 3 cameras, 5 field flatteners, and I'm expecting my 4th mount tomorrow! :sigh:

YIKES!!!! I'm going to stop complaining. Compared to your trials my path has been a breeze. Hope it all gets ironed out soon.

PS: Please let me know if the "rainbow stars repair" helps. I hope it does.

Cheers,
Steve

[Baskevo]

James,

You are, by far, the most snake-bit guy I've come across since coming back to this hobby (which includes forum posting) full-time in 2012. Man, I hope things turn around for you soon. You absolutely deserve a break!

Expectantly,
JT

Haha okay good I'm glad someone else thinks so... I have rattled my brain over and over again, trying to figure out if I am doing something wrong or if my expectations are too high. But every time I get what I suspect is a lemon and I do hours of research, I always come to the conclusion that it is an issue with the manufacturer or something... I usually wait until the forums tell me to send it back, too! I have been happy with high point scientific because they are pretty open to returns and what-not, but at the same time, maybe they are the common factor between all of my faulty gear... I hope I won't find that out soon because that would mean I have another return on my hands : :twitch:

The frustration is totally worth the beautiful images though! I love every minute of this hobby, even when I hate it!

My new mount arrived today, but it's clouds for the next week or so :/ I'm sure I'll have something to post about soon lol