Can we talk about how my nebula photo came out with a weird green halo after I stacked 120 frames?

I shot the Orion Nebula for the first time with my used DSLR last Friday and after stacking in DeepSkyStacker, every star has this green ring around it, did I mess up the calibration frames or is this a known issue with older Canon sensors?

3 comments

3 Comments

mila4051mo ago

Yeah, that green halo sounds like bad darks or flats. Re-shoot those calibration frames with the exact same settings and temp as your lights, Canon sensors are picky like that.

the_holly1mo ago

Feel your pain, that green halo is super frustrating after spending time on a stack. In my experience that's usually a sign of bad darks or flats, especially with older Canons that have some weird sensor quirks. Might be worth re-shooting your calibration frames and checking for any light leaks in your setup.

oscar7431mo ago

Had the same damn issue with my old Canon T3i a few years back. What actually fixed it for me was taking my flats right at dusk instead of in the dark with a light panel. The color shift from the ambient light seemed to cancel out that green cast better. Also triple check your camera settings are locked down the exact same for darks and lights. I forgot once that the long exposure noise reduction got turned on by accident during my lights but off during darks and it looked like a green mess when stacked.