Quote:
Originally Posted by Alex Paul
Dave: If I might..... This is where the darkframe is used by the software... It is shot during the same session with the lens capped off for a total darkframe... When this is used with the stacking program it takes all the dark background with included noise and uses the dark frame for cancelling the noise and turning the background black. I hope this made sense....It dramatically improves the shots by replacing the actual background of the stacked shots with the dark frame.At least that is how I understand it to work.... I can tell you it does work  ....Alex |
Hi Alex
You are correct about the use of dark frames but as I understand it the stacking is a separate issue. I have been using ImagesPlus to process my images and the dark frame subtraction is done to each image before the stacking process. Using a dark frame removes the fixed element of noise from the image but not the random thermal noise, if I understand it correctly. Images will be slightly different e.g. due to fluctuations in the atmoshere, so the stacking process will average these fluctuations out and give a cleaner image. Stacking many identical images will do nothing to improve the quality.
Does that make sense?
Dave