Hello everybody.
My name is Morten, and this is my first post.
I have worked as a VFX compositor and colorist for more than 20 years in the movie industry. A little over a year ago, I started doing astrophotography. At first, I used a DSLR on a cheap tripod, but I quickly ended up with several telescopes, mounts, cameras, filters, adapters and a truckload of cables. I'm currently using an Orion SSP (v1) OSC camera, and Maxim for capturing raw fits.
Up until now, I've done all the image processing using homemade scripts in a VFX software called NukeX. (It's similar to Adobe After Effects). Image calibration and integration has been done with simple algebra, like addition, subtraction and division. I now feel I'm ready to start using more dedicated astro software, and I'm currently evaluating PixInsight. Excellent software, but with a rather steep learning curve!
I've watched all of Harry's video tutorials. Thanks Harry! Keep 'em coming! (I also watched the ones read by Stephen Hawking
, but I like the no-nonsense ones by Harry better)
I have few questions:
1. When creating master calibration frames like MasterBias and MasterFlat, I've found a thread on this forum, saying that one should use average integration, with SigmaClip. Should I use normalization? If so, which one?
Btw. There is a rather substantial difference between using SigmaClip and not using it, when comparing the MasterBias frames with the same screenstretch. Apart from cosmic rays, what are the reason for using SigmaClipping here? Shouldn't at least "Clip low range" be disabled, considering dead/lazy pixels?
2. In general terms, what's the difference between using Median and Average+SigmaClip?
Best regards and clear skies
Morten
