How many hours of data do you actually need for a clean photo? This is a question I asked myself many times over the years. I finally decided to sit down and figure out it, and I'm excited to share my results with you in this video!
First, you must understand that there are many variables in this equation - light pollution, telescope, camera, filters, moonlight, the object you're photographing, and more!
Most of the images in this video were taken in a dark sky (Bortle ~2), with a RedCat 51 (f/4.9) telescope and ASI 2600MC Duo camera. A few of the other photos were taken in a Bortle 6 with an Askar V telescope, ASI 2600MC, and Optolong L-Enhance filter.
Based on my tests so far, I think 8 hours is a good goal. That should provide reasonably clean and detailed images in most cases. However, there will be some targets that are much more dim, and require 16 to 32+ hours of data! This is assuming you can travel to a dark sky. If you are shooting from a Bortle 6+ area, you will need significantly more data.
The most important thing to understand is the concept of Stops. This will be easier if you know photography. Adding a Stop of light will double the exposure time. So if we have 2 hours of data captured, we'd need another 2 hours for an additional stop of light. This becomes problematic once we hit about 16 hours. If we want to add one stop of light again, we now need 32 hours of data total!
Therefore, I think most people should stop around 32 hours of data. The only way to get a noticeable improvement would be to increase the total exposure time to 64 hours. That could take months!
00:00 - Intro
00:54 - What is a Stop?
02:16 - Aperture Explanation
06:28 - Recap
07:23 - Image Analysis Intro
08:14 - Crescent Nebula Comparison
10:56 - Iris Nebula Comparison
11:38 - Pleaides Comparison
12:25 - How Does Light Pollution affect noise?
13:28 - Monochrome vs Color
14:09 - Orion Comparison
16:06 - Elephant's Trunk Nebula Comparison
17:33 - My Recommendations
19:06 - Final Word
