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Tried stacking 200 photos of Andromeda and got a worse result than with 50
Spent an hour capturing 200 frames of M31 with my DSLR on a tripod, stacked them in DSS, and the final image had way more noise than a quick stack of just the best 50 shots. Has anyone else found that more data actually hurts your final image if the quality isn't consistent?
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henry_anderson546d ago
DSS does a median stack by default (which is good for rejecting satellites) but if you've got a bunch of frames with inconsistent tracking or variable sky glow, the median actually picks the worst pixel more often than you'd think. That's why I switched to Sigma clipping in DSS where it throws out the outliers before averaging (you can set it to reject like 20% of the worst frames). Really makes a difference on those nights where the wind picks up or clouds roll through halfway through your session.
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kevin_williams6d ago
Huh, that is weird but I've noticed the same kinda thing with other stuff. It's like when you try to make a perfect playlist and add too many songs, the good ones get lost in the mess. For photos, if the quality of each frame isn't steady, the software just averages in the bad ones and you end up with a blurry, noisy result instead of a clean one. Sometimes less really is more, especially when you're picky about what you keep.
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Exactly. The same thing happens with audio recordings too. If you layer too many takes on top of each other, all the little timing errors and background noise pile up and you lose the clarity you were after. Quality control on the front end saves you from having to fix a mess later.
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