Dodgy Field Flattener?

[Priesters]

Just looking for a diagnosis on this image if anyone can help?  I was trying guiding with my Evoguide 50 for the first time and after a frustrating session (which is another subject) I thought I'd just see what images you can get from it.  I have the Skywatcher dedicated field flattener for the Evoguide so I used that and the attached image is the result. Please bear in mind its only 800s so its not meant to be a work of art! What I did notice is round stars mainly, apart from the bottom left.  Can anyone diagnose the issue?

Thanks

Andrew

[michael8554]

Hi Andrew

To my eyes there are hints of elongation all over the image.

Best to examine a single short exposure sub, stretched if necessary, to eliminate any guiding errors.

Michael

[Chefgage]

I am no expert but u get a similar issue but mine occurs both bottom left and top left. Someone on here mentioned it could be a tilt issue. I have since removed the adapter that has two thumb screws to hold my camera in fitted a screwed adapter in instead. Although early days the images do appear better.

I can only assume that that as it tighten up the two screws it slightly tilts my camera with respect to the imaging train.

[alacant]

On 20/12/2021 at 23:41, Priesters said:

apart from the bottom left

Hi

It depends which channel you choose, but if you can't live with it, it's easily corrected in software.

Here's red, which is the worst, along with an attempt at correction.

But hey, it's a nice shot. Get the colour sorted out and you're there.

+1  @Chefgage's tilt suggestion.

HTH

 

 

Edited December 22, 2021 by alacant

[Priesters]

Thanks all - I’ll have a dabble with those suggestions.