CCD vs Film? Lots of time vs no patience? Alright, this is your place to discuss all the astrophotography what's and what's not. You can discuss about techniques, accessories, cameras, whatever....just make sure you also post some nice photos here too!
Sometime they call a single exposure image from a series of single exposure images as a sub. Basically every single image of your 4x15s exposure image is a sub.
Have a nice day.
Yang Weixing "The universe is composed mainly of hydrogen and ignorance."
for me, i usually determine sub-exposure length in a trial and error manner. i will try different exposure lengths until the histogram peaks towards the right side. The histogram must not bunch on the extreme left or extreme right.
"The universe is composed mainly of hydrogen and ignorance."