Wahugg wrote:The reason I don't do longer exposures is because I have a cropped sensor, and I have to follow the rule of 400 till the star begin to streak across the image instead of the rule of 600.
Normally with a 20mm focal length you can have an exposure of 30 seconds before the stars would streak (600/20=30). But sense I have a crop sensor, I have to use the rule of 400 and I only get to have a maximum of a 20 second expose (400/20=20).
I think this only really matters when doing high quality large prints. I've got an APS-C sized sensor, and have had good results at 18mm and 30sec exposures. The factor that is not included in your math is the output size/type. If you're outputting video, slight streaking is not noticeable because it's naturally blended between frames.
Wahugg wrote:And as far as post shot editing, there is non! I just throw my pictures onto an external hdd, and run them through Quicktime Pro for a time lapse video if that's what I am doing.
James, I am interested in this denoise filter and a quick google did not reveal anything other than it was a form of noise reduction. Perhaps tonight when I have more time I might be able to look into it more.
Post processing can really make the stars jump. Something as simple as an auto levels or auto contrast pass can really help bring out stars.
Denoise and noise reduction are the same thing. Photoshop has some pretty good denoise filters built in. Just play around with the settings until you get something of acceptable smoothness, but doesn't obscure the star details. Its much more helpful if you start at a lower noise level, as high noise is difficult to properly smooth.