A-focal problems with focus

[asset189]

Hi, I know I probably should invest in a second hand DSLR but not possible at this time . I'd like to be able to shoot stills of the moon and larger planets using my Fuji S2960 bridge camera attached a-focally to my 800mm manual dobsonian. When I try this I can never get any focus! Any ideas / tips much appreciated. I can get some success using a smaller Olympus point and squirt camera so I know it should be possible. Thanks

[ronin]

I would suspect that you cannot turn off the autofocus and so the camera goes hunting for an object to focus on/with.

In the night sky things are too dim or (Moon) I guess just too small for the AF to do it's job.

I think for afocal you need to have some idea of what is going on with the scope and camera optics.

If the AF can be stopped you have a chance, however besides the AF you really need everything else to go off.

The sky is to a camera a big black featureless background, so to the camera software nothing to focus on and what ISO and exposure length does it select, calculate and use. It is most likely to flash and give "Error" as a message.

In effect to have an easier time you need to be able to set it to as manual as possible. The problem being that cameras are not generally build with astronomy in mind, even a DSLR is not, it just happens that you can get around the objects put in your way.

[Stub Mandrel]

If it hasn't got manual focus, comb the manual for settings like 'landscape' or some other mode that has a fixed focus at 'infinity'.

[asset189]

Thanks for the replies folks. The camera has manual Controls as well as shutter and aperture modes but don't seem to be a way to turn off AE

[Stub Mandrel]

Try using the landscape or night modes. On some cameras these use a fixed or limited focus range. Make sure its on single shot AF not continuous as well.