|
Two suggestions:
a) Have you taken any daytime terrestrial photos with your set-up? (E.g. take some shots of something on a distant hilltop or building.) It's a whole lot easier to tinker with equipment configuration and settings (focus, exposure, ISO, etc) in daylight than in the dark.
Some equipment choices may simply "not work" on your telescope - e.g. on my telescope, I can't get my webcam to focus unless it is fitted in the 2x Barlow mounted in the diagonal, as the focuser won't extend far enough for direct use of the webcam alone, but my DSLR needs a tele-extender tube but no Barlow or diagonal to reach focus.
Make a note of the focus and exposure settings required to get a reasonable daytime shot, and compare that with what you would get with a conventional camera and lens set-up, so that you basically understand the field of view, exposure and focus characteristics of your telescope rig compared to a conventional camera equipped with a telephoto lens.
b) Is it possible that you are in-focus, but you are massively over-exposing the images? This will give you shots that just look like fuzzy white balls, with no discernible detail.
The Moon is very bright, so needs exposures comparable to day-time terrestrial photography.
If you are using auto-exposure metering, and it is giving exposures of 1 second or so, it will be hugely over-exposed. Try something like 1/30" with "normal" ISO of around 200 for starters. Similarly for the major planets - auto-exposure meters will see 99% black sky / 1% light spot, and will tend to over-expose the bright spot (which is actually the only image you are trying to capture) in an attempt to get a reasonable overall exposure. Again, start with something like 1/30" or 1/15", and experiment with different ISOs (or "Gain" on a webcam) to get an understanding of what exposure is "about right" for the planets. (Save the high ISOs for deep sky objects, until you have got reasonable images of the brighter targets.)
As an experiment, set up your camera with your longest telephoto lens, point it at the Moon, and take a few shots using automatic metering, and again with varying manual exposures. Unless you have a VERY long telephoto, the Moon will only take up a small part of the shot, floating in a lot of black sky, but chances are your best shots will be with "normal" ISO ratings, lens pretty much wide open (f/4 or so), and around 1/30" exposure. That can be used as a guide for shooting the Moon with your telescope - a small adjustment for the focal ratio of your telescope vs your lens (but that's probably only 1 f-stop difference or thereabouts) is all that should be required.
Once you have captured some recognisable images of some key targets, and made a note of the ISO and shutter settings, you can experiment with these as a starting point to get better images.
Hope this helps!
|