Not sure whats going on in these photos. I recently purchased a Tamron 17-70mm lens for my Sony a6000. I love having the ability to zoom now but one thing I’ve noticed is any photo I import into DT always seems to have hyper blue light exposure and/or a huge amount of weird black grain that I am not sure where is coming from.
What fixes this is adjusting the Hue Shift slider in Color RGB which resolves the issue immediately but then makes me adjust the exposure down to compensate. So it definitely seems like maybe a profile issue Darktable has with my lens?
Not entirely sure but I’d be curious what others think / if anyone else has this lens or this issue
Attached these photos to show what I mean:
f4.5 w/ ISO 3200 for the first
f2.8 w/ ISO 3200 for the second
Thinking I might just return the lens since theres a few different places online talking about bad profiles
Looks like all those pictures have been taken under blue led light. That kind of light is difficult to handle:
it’s very monochromatic, so the colour is out of gamut for most colour spaces;
there’s an overdose of UV in it, for which the camera sensors are sensitive, but not our eyes; that falsifies the colours wrt what we see…
See This episode of “Editing moments” by @s7habo where he shows a way to handle this. Perhaps post one the images as a play-raw (if you have the raw files) so others can practice on them?
In summary,what you show is not a problem with your camera, and even less with your lens (and what do you mean with “bad profiles” concerning that lens?)
The lens in use should not have any effect whatsoever if you turn off the lens correction module… that’s the only bit in DT that uses any lens data AFAIK. Have you (if possible tried taking the same images with any other lens? I’d be very surprised if it makes any difference (but I’ve been surprised before!)
When I say “bad profiles” I guess I’m just guessing at that but darktable will originally have the image incredibly grainy and noisy as in the first images but then upon sliding the hue slider slightly then double clicking to reset it it fixes the issue entirely so it seems like something at the software level is happening.
In that case, if you want advice on how to handle such images, post a raw as a play-raw in the processing section (with an appropriate license so others can post their results).
The images you pasted are too small to see what’s really going on, and don’t have any metadata attached to them.
That sounds like something I’ve noticed before - that only affects this sort of image with heavily out-of-gamut colors. If you just turn on color balance rgb, but don’t touch any sliders, does the issue also resolve itself?
And, if you turn color balance rgb off again, does it come back?
If yes to both these, it’s definitely a gamut issue, (not lens at all) which I think can be also sorted with the gamut compression in color calibration. It seems that color bal rgb does something sort of gamut related operation that straightens out this sort of issue.