Raw Histograms

[SodaAnt]

Are there any cameras today that show an in-camera histogram based on the raw image rather than based on the processed JPEG image?

 

[nmp]

Sure. Will only cost you $60K:

 

[L Gebhardt]

I don’t think any of the main brands offer this. For a Sony alpha series I rely on the zebra stripes as a reasonable proxy for when it’s clipping. You can see the raw histogram in apps like rawdigger to help calibrate this. It’s not perfect but better than nothing.

 

[koraks]

in-camera histogram based on the raw image

Have you contemplated the interpretation of a RAW_based histogram? What does it say exactly, and most importantly, what are its limitations? Maybe this forms part of the explanation why the functionality is missing from all consumer cameras and most 'pro-sumer' devices as well.

Perhaps at this day and age, it would make the most sense to look at the cine industry where information concerning raw capture is particularly relevant, given the heavy emphasis on post-processing, color grading etc. and the separation (also very strongly in organizational terms) between capture and post-processing. I wouldn't be surprised if rummaging through whitepapers by e.g. Arri would yield some interesting information.

 

[Alan Edward Klein]

I don’t think any of the main brands offer this. For a Sony alpha series I rely on the zebra stripes as a reasonable proxy for when it’s clipping. You can see the raw histogram in apps like rawdigger to help calibrate this. It’s not perfect but better than nothing.

Larry I:m confused. Why are blinkies (zebra stripes) from RAW but not the histogram?

 

[L Gebhardt]

Larry I:m confused. Why are blinkies (zebra stripes) from RAW but not the histogram?

Alan, I'm not positive they are, but I believe I've read that the sony alphas use the green raw channel to display the zebra strips. In testing with the A7R3 and A7R4 this seems correct. So I set the Zebra Level to Custom2 which I setup as Lower Limit 107+. If I recall correctly 109+ also works and might be a bit more accurate but the 107+ seems to offer a bit of safety for small specular highlight borders. In years of shooting with this I rarely have over exposed images even when apply positive exposure compensation.

My speculation on why they do this could be related to the video origin of zebra stripes. Some sony video cameras support a raw output mode which won't have a jpeg frame so maybe they engineered it in the video cameras and ported all the code to the stills centric cameras. It's just a guess and I could be wrong on all of this.

Possibly related to this is the green channels seem to be exposed a stop more than then red and blue channels when looking at the raw histograms for a daylight balanced light. If the green channels are more sensitive than the others maybe that's why they can safely just monitor them which would allow a more responsive display with the processing power they have.

Edits: As for why the histogram is from the jpeg, my guess is the programmers wanted to keep the review process responsive and rather than demosaicing the raw data for raw files and using the for actual jpeg for jpegs they went with a simple and quick solution that works on either. I think they newer processors could handle the process quickly but the early camera processors were very limited in processing power. The code running on these cameras is almost certainly not rewritten for each model and probably contains a lot of code written for the earliest cameras. Also changing functionality would require lots user testing and add cost, none of which would sell more cameras.

Also, here's a link that could be the source I'm remembering: https://www.dpreview.com/forums/thread/4259130

 

[nmp]

There is something called Unitary White Balance that allows one to mimic raw but personally I have no idea how that works. I suppose that is what a calibration in Rawdigger does.

:Niranjan.

 

[SodaAnt]

There is something called Unitary White Balance that allows one to mimic raw but personally I have no idea how that works. I suppose that is what a calibration in Rawdigger does.

:Niranjan.

That gets you closer to a raw histogram, but at the expense of the preview image looking a sickly green on many cameras.

 

[Steven Lee]

@SodaAnt See what Koraks said above: video people need this. I would look for a camera with robust video capabilities and see if you can configure it to shoot stills in Log or S-Log mode (sometimes called "picture mode" or "profile") and if a live histogram is offered. It should be very close to what you want.