So I"m really having trouble focusing since I've gotten the ASI6200 and EAF. And by trouble I mean I have yet to have a successful night. My stars appear like giant christmas bulbs. So I have a few questions...

I"m wondering if the narrowband Lenhance filter I have in front of the camera is causing issues? I maxed out the exposure time for the autofocus utility to 20 seconds. And I've played around with maxing the gain to 100 and down to 0.

The trouble is, even without running the Autofocus program, even when I do a manual focus so I can see the images, they all appear just as faint streaks. It's almost like the exposures are too long and there's star trails..which doesn't make much sense the expsoure at max is 20 seconds (I even shortened it to 5 seconds)

  1. The other problem I have is this... So got to what is best described as a passable rough focus (still big bulbs for stars..but better than nothing) so I made note of the step size, (30555) and then let the autofocus do it's thing...It said successful.... It clearly lied to me... Do I have to run this multiple times or somthing? Why would it not just keep going until it was 100% perfect? How do I know how many times to run it?

  2. Will the step size generally be the same each time I go out? Right now I think the best I've gotten (still will crap stars) was 30555-32000 Shouldn't this number be the exact same for each time I go out? Or is it normal to change?

    Mr_Cellophane autofocus works best for me if i roughly focus the stars so they are as small as possible and afterwards run the autofocus routine. Big bulbs do not help here and ASIAir will have a hard time finding any good reference, in which direction and how far it has to rotate the focuser.

    Mr_Cellophane Why would it not just keep going until it was 100% perfect? How do I know how many times to run it?

    Unfortunately, that is not how it works. Try to focus as good as you can manually then try autofocus again. Then it should not be necessary to run autofocus over and over again.

    Mr_Cellophane Shouldn't this number be the exact same for each time I go out? Or is it normal to change?

    Yes, it is normal that they change. For example, if temperature changes from session to session even if it is unnoticable by your bare eye. If it's warmer outside, your gear's material expands and the if it's colder outside, it will contract. This will affect the optical train and thus the focus point will be affected as well. Another aspect is the seeing: earth's atmosphere causes wobbly stars, sometimes, more sometimes less. This affects the focus position as well.

    Olli

            AstroDude42
            Thanks!! My problem is that when I try to do it manually, I only see a VERY poor blurry grainy image that has a lot of star streaks/trails... I can't even get the manual method of taking the images to get small, sharp stars. All of my focus images are trailed and really really grainy..

                Mr_Cellophane that sounds like the sensor of your main camera is not in ideal backfocus position. Your best bet is to check with the manufacturer of your scope what that distance should be and use some adapter rings to bring the camera into that position. Good luck!

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