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Old 27-01-2023, 10:31 PM
Startrek (Martin)
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Startrek is offline
 
Join Date: Dec 2017
Location: Sydney and South Coast NSW
Posts: 6,597
Quote:
Originally Posted by Emuhead View Post
Hi all,

I have these really odd looking triangular star shapes that I once thought were pinched optics, which after freeing up the mirror to the point its almost floating around in its cell, i can confirm if it is pinched optics, it not the mirror clips. I also dont think its collimation as im doing the same thing i usually do. Im starting to suspect it might be the reducer im using. Ill be testing that theory tonight, but in the mean time.. what do you think the image attached looks like? In the lower left you can see each star splitting into 3.

Gear:
Skywatcher Quattro 10"
Starizona Nexus 0.75x Reducer
ASI2600MM
EQ6R Pro

Also, the vignetting cant be from the filters as they are 50mm Antlia's with an OAG-L, so im guessing thats either unavoidable light falloff or maybe the light cone being restricted by the 2" focuser. Any ideas there also appreciated. Id like to eliminate that if altogether if possible.

Im starting to get why most people just get fracs.. in my own experience they are just so much easier to get good results out of.
I feel your pain and frustration
The amount of times Ive read folk having trouble with f4 Newts on various forums you could fill a book
I was advised by a guy at Bintel back in 2016 to go f4 for imaging.I didn’t take his advice and went f5 and so glad I did with all my scopes 6” , 8” , 10”and 12”
A snack to collimate and rarely have any optical issues.
If I can offer any advice in regards to a good quality coma corrector for f3.5 to f5 Newts it’s the TS Optics GPU coma corrector ( recommended by Diego from Sidereal Trading )
There not cheap but the results are excellent, absolutely no coma and stars nice and tight , a quality optical instrument ( I used a Baader Mk3 for 3 years and struggled with it )
Unfortunately in your case A-Z trial and error elimination testing of the optical train is the only solution to find the problem.
Good luck with it and I’m sure you will get to the bottom of the issue in time

Cheers
Martin
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