Overall, I think you need to read more on the subject of taking images of
planets and how to do stacking, but here's a short answer.

First, it sounds like you're summing the images together, not stacking in the
sense that those planet imagers, including myself, do with programs like
Registax.

Second, to reduce noise significantly, you need to get hundreds of images.
Reducing noise is a statistical thing, and in statistics you need to have many
samples or images in order to get any significant effects. 30 samples is sort
of a Rule of Thumb minimal number in order to get meaningful results. You can
do this with a digital camera, but a better way is to use a webcam. It's a
question of time really. In the time you can take a dozen or so images with a
digital camera, you can take hundreds of images with a webcam. But the Big
Problem is the lack of tracking. This severely limits your ability on planets
when it comes to taking a lot of images. One solution is to get an equatorial
tracking platform for Dobs - look on the web for these. I think in the long run
you're going to find it too frustrating to do it with your current setup.

Third, use a program like Registax, which can automatically select the best
frames, align them, and stack them for you once you learn how to use it.
--
Sincerely,
--- Dave
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It don't mean a thing
unless it has that certain "je ne sais quoi"
Duke Ellington
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"Amyotte" wrote in message
...
I have an 8"f6 Dob and a scopetronics setup for my digital camera. I am able
to take 1/30 second shots of say Jupiter and Saturn. Unfortunately I do not
have a guiding system to track so stacking multiple images becomes a problem.

There are fantastic images taken by others where a 1000 images are stacked and
the detail is incredible.

I have tried to stack multiples of the same image with little luck in
obtaining anything but an over exposed image. A couple of image stacks may
bring out some detail. I understand that multiple images can reduce
background noise and grabbing a group of saved images during a window of great
seeing can also help.

For me to try stacking do I set the shutter speed to say 1/250 sec and
although the image, when dumped to the computer, is very faint would I then
stack 100 copies to grab the detail and increase the brightness?

Not sure if I have worded my question correctly but I am hoping someone will
know what I mean.

Regards
Brian