Histograms, JPEG's & In Camera Settings

Thumpermawer

I normally don't use histograms when metering for a scene, unless it's a static composition like a landscape or where I have control over the subject and lighting (still life, portait etc).

I had never really thought about how the histogram is generated, but since it is based on the JPEG preview of an image (even if you shoot in RAW only as I normally do) the "blinkies" showing clipped high/low lights might not be as bad as you think.

I shot the image below on a day trip without giving it too much thought or planning. It wasn't till I was reviewing images later on that I noticed that 100% of the sky was blinking, and was about to delete when I got distracted. After uploading the images from the card at home, I liked the image and thought to try and restore, even though I was expecting the full sky to be a washed out mess. As you can see, there's plenty of detail there so it's made me question how much I should rely on the histogram/blinkies when I do use them to shoot.

Gilnockie Tower, Clan Armstrong Centre.jpg by Thumpermawer, on Flickr

Will adjusting the image settings in camera - which normally only affect JPEGs - have an effect on the histogram? I'm thinking I should set everything to as dull as possible, to try and emulate an unprocessed RAW file.

snerkler

Most settings that you apply will be only be applied to jpeg, the only thing that will directly affect the look of the RAWs are exposure and WB (both of which you can change in PP of course, WB usually without any penalties). Things like sharpening, clarity, contrast, picture settings, d-lighting, and tone curves (if your camera has them) will affect jpeg only. That being said, if you use the camera manufacturer's PP software then they can emulate certain effects (such as d-lighting) on the RAW files.

What your example shows is just how much more detail RAW captures than jpeg, which is why I always recommend shooting RAW. People have been asking for in camera RAW histograms for years but to date it's fallen on deaf ears/no-one's found a way to do it/it takes too much processing power. Histograms are extremely useful, but you have to be aware that they are also 'flawed'. If you're a RAW shooter I would always recommend turning off all effects (d-lighting, vignette etc) and not changing contrast and clarity too much so that your histogram looks as 'natural' as possible. I guess you could make your jpegs look less contrasty if you want to mimic the 'look' of the dull RAWs, but in PP you're not going to leave the RAWs like this anyway so some might say you're better off leaving the jpegs alone as the histogram will give a better representation of what your final histogram may look like.

Thumpermawer

Yeah I was using the previews as a guide to how an image could look, but I'm starting to find this less useful as time goes on. Having the histogram as accurate as possible would be far more useful to me now, to be sure of eeking out as much of the shadows before clipping highlights and vice versa.

I'll try minimising in camera enhancements to see how much, if at all, that affects the previews while out shooting.

You never know, maybe Canikon will manage to include RAW histograms in their FF mirrorless cameras