3 ms·
I think the answer is that the raw data has too much dynamic range. The stars are so much brighter than anything else that a naive linear scaling from the nativ
by Cerium 4y ago
I think the answer is that the raw data has too much dynamic range. The stars are so much brighter than anything else that a naive linear scaling from the native depth to 8 bit results in all the shadows getting washed out and only the highlights showing. Instead, the "stretched" seems to be compressing the highlights to allow the shadow data to become brighter.
- jcims 4y agoN00b astrophotographer here. I can't see the images but this sounds correct. (Edit: paste the two images into an image editor and look at the histogram. You'll see it)
- mturmon 4y agoProbably true, and analogous to gamma correction (https://en.wikipedia.org/wiki/Gamma_correction https://en.wikipedia.org/wiki/Gamma_correction) although they don't specifically say whether the range-compressing transformation that they are using is a power law.