out of focus?

[Gonzo]

I'm pretty sure this is way out of focus, unless I'm having other issues? Megrez 72 + Atik314L+

 

 

Also the link to the fits file:

http://33b7583a5f908e61a232-6b8a975948e4f6a1f524753201982401.r85.cf2.rackcdn.com/Polaris_outoffocus.fits

 

 

[Tinker1947]

Do you use a Bahtinov mask........

[Gonzo]

Just now, Tinker1947 said:

Do you use a Bahtinov mask........

I do not, I use the autofocus in Kstars. It was working the other day quite fine, something might have gone wrong in my system.

As for the mask, it wouldn't help me much I 'm afraid as my observatory is about nearly 9 hours driving away from me.... It's in Germany. But thanks for the suggestion.

[vlaiv]

I don't think it is a focus issue. Mind you, I don't have much experience so I might be totally wrong on this one, but cores are quite sharp, diffraction spikes around the brightest star are quite thin (when you manipulate contrast you can see bunch of them going in all directions), since these form before reaching focus while rays are still parallel I would expect them to be out of focus as well (this happens on newtonian and 4 diffraction spikes).

This to me looks more like close to sensor kind of reflection that could happen if things were starting to fog up (similar thing happens if your filters are not AR coated properly but halo happens to be much larger - due to increased distance to sensor). If it is a cooled camera (and I believe it is) maybe it is consequence of the moisture in ccd chamber?

[Gonzo]

ok thanks for the input, appreciated. Maybe it's dew after all...

[ollypenrice]

Where does the red come from?

Olly

[Gonzo]

I use the software 'Fits preview' on my Mac, I must have clicked on something by mistake. Don't worry about the red dot.

[vlaiv]

I thought that red represents overexposed pixels, this can also give some indication of out of focus, if overexposed pixels are always circles then you have perfect focus, in your case there is a bit of defocus - some stars have little doughnuts as overexposed parts. Also, since you are using refractor, is proper filtration in place? Maybe halo is coming form unfocused IR or something like that (But you did mention that you had your setup working last time, so maybe if you have automatic 5 slot filter with L, RGB, you missed filter position and went on to record L with no filter at all? Empty filter slot?).

[Gonzo]

I have a 5 filters wheel, with 5 filters in it. It was working all fine the other day, excellent focus. Not sure what's going on, hard so actually see when the observatory is located several countries away.... lol

See this post:

 

 

[Gonzo]

Thinking out loud there, could the brightness of tonight's moon be responsible? or am I just talking non-sense there?