Low Light / Astrophotography Manual Focus Assistant

[dmilligan]

First off, kudos to you guys for making such a wonderful piece of software. I've been using ML for about 3 months now and I don't know what I would do without it. It makes my cameras 10x more useful.

As an astrophotographer who shoots a lot in very low light and often with manual focus only optics (such as a telescope). I would find it very helpful if ML could somehow assist me in achieving focus. Focusing with a telescope is a long, arduous, trial and error process. I think it could be sped up and accuracy improved with the help of ML. Here's basically what I do to get focus: take an exposure with the shortest duration that I can and still get enough image to judge focus (usually at least several seconds, if I'm photographing something really faint could be as long as 30s, also with the 2 sec timer and mirror lockup so I don't get any shaking). Then move the focus a little and take another picture and so on and so forth until I feel like I can't get it any better.

So here's my request: a manual focus assistant. I takes an image and analyzes focus and then says to you "move the focus" then it takes another, compares to the previous and says either "keep going", "no that's worse go the other direction", or "that's as good as your going to get".

I think this is simple enough it could almost be accomplished with a picoc script. I looked at the API a while back, but I don't really remember if there were sufficient focus checking functions to accomplish this. The other issue would be that analyzing focus in an image that is mostly a star field is a bit different from a "normal" subject (though theoretically much easier since you just have lots of little point sources of light you can check)

The second part of this would be an automatic mode for lenses that are AF but there is not enough light available for AF. It would basically do the same thing except fully automatically, then it would lock the AF, or just tell the user to switch the lens to MF so the camera doesn't try to AF on the next shot and screw it up.

Thanks!
David

[a1ex]

Enable trap focus and you'll get the assistant on the screen

[g3gg0]

with 1000mm focal length changing focus will cause so many vibrations that it is impossible to see anything on screen.
i have the same problem with a maksutov