M45 Weird Halos

[AndyThilo]

So I shot Pleiades last night. But as I've seen before from an earlier short session, the main stars have halos with missing bits, all at the same angle (hard to explain).

Any ideas why I'm getting this?  Scope is an Esprit 80 with the Skywatcher flattener, CLS-CCD 2" filter and ASI 294 MC Pro camera. I'm wondering if it's simply overexposure? The lights were 120secs, is that too much?

M45 Pleiades V1 30-12-19 by Andy Thilo, on Flickr

 

 

[david_taurus83]

I believe it's something to do with the clips or spacers holding the lens in its cell. I could be wrong but it's what I've read. My WO71 does it but not overly pronounced on one side like yours. I've not seen any Esprit images with it like yours. Can it be returned?

[AndyThilo]

Returned? I would think so yes, it's only a few months old. TBH i've not noticed it on any other images, only this one with super bright stars. Maybe I'll speak to Rother Valley Optics who I bought it from and see what they think. 

[MarcusH]

Those look similar to the artifacts Tommy Nawratil describes in his article about fine tuning the Skywatcher Esprit 80 / 100:

http://interferometrie.blogspot.com/2014/08/esprit-tuning-how-we-finetune-esprit80.html#!/2014/08/esprit-tuning-how-we-finetune-esprit80.html

A very intresting read, btw.

[AndyThilo]

Wow that really is what I'm experiencing! Thank you! I'm going to email Rother to find out how I can get it sorted. Thanks for the article

[MarcusH]

I'm sure they will sort it out for you.

Can't help thinking that these "quirks" are known as both Teleskop-Austria and FLO offers an opt-in for an optical bench test for the Esprit line-up before dispatch….

[AndyThilo]

Yeah I didn't get the option to do that with Rother. They've emailed me this morning so hopefully it will get sorted soon. 

[AndyThilo]

Dropped the scope off at Optical Vision this morning (distributors for Skywatcher in the UK). They will look at it tomorrow hopefully and let me know what's happening. Their warehouse there :O, thousands of boxes of Skywatcher mounts, scopes, everything :D. 

[AndyThilo]

Well I have a shiny new Esprit 80. Not sure how much they checked mine. Hopefully this one will perform better! 

[MarcusH]

Good to hear !

It was probably the fastest way to get you back to imaging. 😉

[AndyThilo]

Yeah it's the only scope I have so I was lost without it. Fortunately they're not far from me so I dropped it off and picked up the new one.  Hopefully get to test it on Sunday looking at the forecast.

[AbsolutelyN]

Weird, never seen this before, hope you got it fixed. This is my Esprit 80. 

[AndyThilo]

Hope the new is better for sure, otherwise that will be also be going back and I'll have to consider whether I want a 3rd. Or insist another gets sent off for proper checking and alignment. It's also evident on my California Nebula photo, exactly the same pattern. And the M45 was with a CLS-CCD filter, the California with a L-Enhance.

NGC 1499 California Nebula by Andy Thilo, on Flickr

 

 

Edited January 10, 2020 by AndyThilo

[AndyThilo]

Well...[removed word] :(, excuse my language. New scope is even worse. New on the left, old on the right. New was shot with L-Enhance which is the wrong filter but I just wanted to see the star shape. Halos are better but new has 2 distinct spikes opposite each other. Sigh....... Is it too much to ask for a good quality scope when you pay £1100??

[AndyThilo]

I'm wondering, could my scope rings be causing this issue? Could they be too tight, is this the reason why SW don't supply the Esprit 80 with rings? Hopefully I'll get clear skies tomorrow evening to test. I'll have to ditch the guide scope but should be able to get 60sec subs with my EQ5 Pro unguided.

[david_taurus83]

That's disappointing. Sounds like OVL just simply replaced the other one without investigating. Could be overtight scope rings adding pressure. You could also try just the camera with no filter in the optical path to try and rule things out. Are you using a dew strap? I'm going to add another dew strap to my scope on the tube to also reduce the chance of pinched optics. I always run my objective dew strap on full bore BTW.

[AndyThilo]

45 minutes ago, david_taurus83 said:

That's disappointing. Sounds like OVL just simply replaced the other one without investigating. Could be overtight scope rings adding pressure. You could also try just the camera with no filter in the optical path to try and rule things out. Are you using a dew strap? I'm going to add another dew strap to my scope on the tube to also reduce the chance of pinched optics. I always run my objective dew strap on full bore BTW.

 I'm not sure what testing they carry out, be they certainly didn't test the new one as I asked. They stated that they're all calibrated/tested at the factory....

I've taken the rings off and put the original foot back on. TBH the only thing I need rings for are the guider. If this cures it then I'll get an OAG. I have a full diameter dew strap fitted, controlled by my pocket power box. I'll try it without a filter as well, although the original had the same star patterns with 3 different filters, but it's a good suggestion. Just need some clear skies! I did think about getting an artificial star but not sure how much that would help me. 

[david_taurus83]

4 minutes ago, AndyThilo said:

 I'm not sure what testing they carry out, be they certainly didn't test the new one as I asked. They stated that they're all calibrated/tested at the factory....

...in a different climate, boxed, stacked on a pallet, forklift round a warehouse, forklift to a shipping crate, crate to lorry, lorry to port, crate to ship, a few weeks at sea, and repeat in reverse once it gets here before shipping to you!

[AndyThilo]

Yeah I know, I refrained from commenting on their idea of factory calibration lol. In hindsight I wish I'd bought from FLO and used their optical test option. I'll see what happens without the rings and filter. If it's still bad then it's going back for a refund. I'll then have to decide what replaces it. Either another from FLO with the optical test, or something else, maybe a WO GT81. 

[MarcusH]

Yikes, it's starting to look like the optical bench test should be mandatory rather than optional...

Sorry you've been put through all this trouble. What are the odds of getting two bad copies of the scope ??

But at least this have showed all potential Esprit buyers the value of a optical bench test.

[AndyThilo]

Yeah it's not looking good lol. Hopefully I get some clear sky tomorrow to take some test shots of Pleiades to compare with the scope having no rings and a basic UV/IR filter fitted. On the plus side, I might be having it checked by a certain optical master who lives very close to me :). 

[saac]

2 hours ago, AndyThilo said:

Yeah it's not looking good lol. Hopefully I get some clear sky tomorrow to take some test shots of Pleiades to compare with the scope having no rings and a basic UV/IR filter fitted. On the plus side, I might be having it checked by a certain optical master who lives very close to me :). 

Drop Skipper Billy a note , if I remember correctly he experienced a similar problem, albeit on a different setup, same target thought from what I remember. 

Jim 

[MarcusH]

On ‎10‎/‎01‎/‎2020 at 15:22, AndyThilo said:

Fortunately they're not far from me so I dropped it off and picked up the new one

 

3 hours ago, AndyThilo said:

I might be having it checked by a certain optical master who lives very close to me :). 

 

Mental note: If I ever decide to move, make sure that:

• There's a big distributor of astronomical equipment nearby
• There's a optical master right around the corner

😄

[AndyThilo]

3 minutes ago, MarcusH said:

 

 

Mental note: If I ever decide to move, make sure that:

• There's a big distributor of astronomical equipment nearby
• There's a optical master right around the corner

😄

Yeah it’s definitely a plus, but I’d rather not have the hassle in the first place lol. 

[AndyThilo]

Well it’s defiantly not the scope rings, which is good. Tested with just a UV/IR filter and stock foot. Taking it back tomorrow and will demand  another new one. Last chance before I demand a full refund and buy one from FLO with the optical test. Or maybe change to something else like a WO 81GT. 

Photo is stretched 60 sec shot of Capella just to highlight the issue.