Seeing holes in stars after HDR Composite

[pfile]

holy smokes, i can't believe i missed the fact that the images were not registered properly. i should have blinked them. thanks andres.

rob

[Andres.Pozo]

I use a mask and APT software which has a tool to focus with. The way it works is you align 2 circles on top of each other and it's focused.

The seeing was not great, but better than some nights, I could not get it exact, but it was pretty close.
So I am confused about why it looks out of focus.

I don't know how you focus, but there is something clearly wrong in your methodology. Simply by watching the stars, you can see they are clearly unfocused, but I have also measured the FWHM using DynamicPSF and the result is over 10". Typical FWHMs in amateur skies are about 2-4". In a bad night it can go up to perhaps 5-6". 10 arcseconds with nice round stars means the telescope is not well focused o collimated or both.

[sctall]

This is excellent
Thanks

I used the PSF on my subs and they avg ~ 10px. Not good.
I should say, although this is an inhibiter to focusing, I don't see well at night, so these tools should help. Once the star gets looking pretty good to me I cant tell the diff. But I should be able to work around it with software.

I took another persons image, and using his parameters, PSF showed an avg of 2px. So it is working fine.
I have a motofocus to focus with, so it should be easy to improve.
So this is a good place to start.

I am surprised to see a significant diff in focus, in such small changes though.

thank you much!!!

Scott T.