Re:Features that more cameras should have
by sudosysgen on Wednesday November 17, 2021 @09:11PM
(#29261315)
What you want is bracketing. Most cameras do it, my A7ii does for example. Cameras have enough dynamic range nowadays that you'll get close enough.
Alternatively Sony has "DRO Bracketing" which basically does what you mean with the histogram, but a bit better.
Re:Features that more cameras should have
by LorenPechtel on Thursday November 18, 2021 @04:51PM
(#29271086)
A lot of cameras have bracketing--even the bridge camera I carry while hiking has it. I'm talking about HDR-aware bracketing that decides how many shots to shoot rather than simply shooting a fixed range. Imagine a shot in a building looking out the window with sky visible. You could have a range of 10 stops or more.
Re:Features that more cameras should have
by sudosysgen on Thursday November 18, 2021 @07:59PM
(#29272584)
A modern full-frame camera will have 14 stops of dynamic range. Five shots 3 EVs apart is enough, you'll get a total of 29EVs of dynamic range. Well beyond your ability to actually tonemap properly. That's equivalent of, practically speaking, going from a shutter speed of 10 seconds to 1/3200ths of a second, and still having fourteen stops of headroom left (7 at both ends).
FWIW I can take pictures in a room with a window looking at the sky and change the exposure to clearly see both the sky and the room without even bracketing on a full frame camera.
Re:Features that more cameras should have
by LorenPechtel on Friday November 19, 2021 @01:20PM
(#29280463)
Yeah, if you have a camera that pricey you could do it that way. Note, though, that you don't want to use all your dynamic range as the quality drops off.
Re:Features that more cameras should have
by IshKebab on Wednesday November 17, 2021 @06:00PM
(#29259980)
Why does stacking them require human intervention? For a completely static scene I would have thought the algorithm is fairly simple and unambiguous.
Re:Features that more cameras should have
by nitrogen on Wednesday November 17, 2021 @06:10PM
(#29260082)
Tone mapping is very much a subjective process. There's no one "HDR" algorithm. At best the camera could convert everything to linear or logarithmic light and save in OpenEXR or something like that.
Re:Features that more cameras should have
by IshKebab on Thursday November 18, 2021 @06:20AM
(#29264242)
Tone mapping isn't HDR though. It's mapping HDR to standard dynamic range.
> At best the camera could convert everything to linear or logarithmic light and save in OpenEXR or something like that.
Yes exactly. That's what HDR is.
Re:Features that more cameras should have
by notJim on Wednesday November 17, 2021 @06:06PM
(#29260031)
I'm not sure if this is what your parent meant, but I think it can require more or fewer frames, with more or less spacing depending on the camera, and on the dynamic range of the scene. Currently (at least with Fujifilm) you have to manually program all this in.
Re:Features that more cameras should have
by LorenPechtel on Friday November 19, 2021 @01:16PM
(#29280422)
Exactly--all it requires is a quick inspection of the histogram to tell if you need another shot, but that's problematic for a human unless you can do it all remotely as you don't want to touch the camera if possible. It would be a trivial task for the camera itself.
Re:Features that more cameras should have
by LorenPechtel on Thursday November 18, 2021 @04:53PM
(#29271113)
The initial stack doesn't require a human. Compressing the dynamic range to produce a useful output is still a task that AFIAK is best performed by a human.
Re:Features that more cameras should have
by mgdlbp on Wednesday November 17, 2021 @04:54PM
(#29259346)
I've seen several Fujifilm bridge cameras with in-camera stacking; not sure about the rest of their line.
Re:Features that more cameras should have
by sainotbot on Wednesday November 17, 2021 @05:23PM
(#29259636)
Pretty sure you can choose DR100, DR200 or DR400 since the X-T1. My X-T4 definitely has it.
Re:Features that more cameras should have
by spaetzleesser on Wednesday November 17, 2021 @05:31PM
(#29259708)
That’s not really HDR though.
Automatic shooting of HDR exposures. Stacking them requires some human intervention and shouldn't be done on the camera, I'm simply thinking of the shooting. You put your camera on a tripod, select HDR and push the button. It shoots a frame and checks the histogram--are pixels falling off either end? If so, adjust only the shutter speed and shoot again. Keep doing so until the slowest shot has nothing falling off the dark end and the fastest shot has nothing falling off the bright end.