[quote=JesusSaves;1173492]Dear Paul,


Thank you for your reply. See below for full details on photo graph.
File Name
Orion forum.jpg
Camera Model Name
Canon PowerShot G6
Focal Length
7.2mm

Paul:

You have figured out something that few people appreciate: The the Sony 7.1 Mpixel 1/1.8" CCD is very decent for light-duty astrophotography. Your 7.2mm focal length is the equivalent of f=35mm for a 35 mm film camera. I still have the Olympus SP310 with the same CCD, which I used to make some neat pictures of the galactic plane by stacking 20 pictures (15 seconds each) on site at 10,000 ft elevation and a very dark sky using the IRIS software.

The bad news is that the aperture on your G6 is only 7.2mm/2 =3.6 mm and you are limited to iso400.

If I were to take the same shot with my Nikon D40 and a Nikkor 28 mm f/2.8 (equivalent to f=42 mm), almost the same large field of view, but with a 28/2.8=10mm aperture (gained factor 8 in area) and you can go to iso1600 with less noise than the G6 at iso400 (gained another factor of 4). While you don't gain a factor of 32, the results are stunning, even under light polluted conditions. This was first shown by Christian Buil ( look for the IRIS web site and his name). The IRIS software is free. Try stacking some of your G6 pictures. You will be amazed.

I have stack 20 exposures at 30 seconds each using the D40 with a 105 mm f/2.5 lens. From my backyard (visual condition +3.5 on a good night) I get to stellar magnitude +14. Pretty neat for satellite, astroid and comet hunting.

hha