Hello .
I have a question about tilt and im not sure about what i found on the Web.
I have a new sharpstar 13028hnt and my stars are elongated all over the image . I think it's tilt because my backfocus seem to be ok . 55.6mm
My question is : does tilt affect the overall image quality or just the stars ? If the answer is just stars , i can live with that and use blurx
Thanks
It might be good to show an image of the elongation you are talking about; it's difficult to identify just from your words.
Tilt will affect your overall image quality.
Clear Skies.
This sounds more like guide error than a spacing issue.
I was just testing yesterday and forgot to save an exemple .
My guiding was good . Around 0.6
Still doesn’t sound like a spacing issue. No spikes anywhere in the guiding graph for the session. Have you blinked your frames? You could get a spike or two and still have a good RMS.
Tilt generally manifests as an uneven distribution of star sizes across the frame, as some stars will be in focus and others not.
Spacing issues will generally manifest as elongated stars but the direction of elongation will either radiate out from the centre, or form concentric rings around the centre, depending on if the spacing is too close or too far.
If you have elongation that is all in the same direction and magnitude across the frame, that would point to a guiding/tracking issue.
Of course you can get a combination of all the above which makes things very tricky to pin down.
I have the same scope. Perfect focus is really important, otherwise alls stars will be elongated. I use the ZWO EAF and it needs to be within 10 steps precise.
Also look at the collimation. I use the OCAL collimator, works fine.