What Is Happening Under The Histogram Hood

IMHO adding "... and how to use it", or even to start with "how to use histograms" (while shooting, culling, editing) might be useful.

yes, that was an option but my purpose for this thread is to hopefully help anyone not sure what a histogram actually is and represents to get a good and proper understanding first before discussing how to use it.

How to then actually use and/or interpret the histogram is probably better discussed in a separate thread imo.

Readers may strongly prioritize "how to" and "what to look for" - in case you would like to write an article on the topic for this site. ;)

Thank you for the suggestion but you are very much more qualified and experienced than me to write such an article on the topic for this site :-)

That’s the problem with the histogram! I can’t tell which blown highlights are the important ones.

The other, albeit a smaller problem, is that everything in the camera histogram that is between the highlights and the shadows has low usability.

One thing that should be mentioned is the x-axis nonlinearity. It is different for in-camera histograms depending on the color space chosen for the JPEG preview image, In Ps, it changes with the color space of the image. In Lr, it is the sRGB nonlinearity, even though the primaries are the PPRGB primaries.

Zebras are better for that.

I am logged in and this is what I see this very minute::

what the reply editor said for my image above:

![What I See](http://kronometric.org/phot/temp/what%20i%20see.jpg)

I can see images in many other posts here.

If you click on the question mark icon at right when in the reply editor there are several ways to code images.

Can I assume that a JPEG-derived, in-camera histogram without clipping guarantees that there will be no clipping in the raw file?

No, unfortunately. Try taking a picture of a bright deep blue flower.

Yes, something I have told those buggers at Canon for over a year, since I bought my R5. I fully expected it would have zebras… I thought that was one of the key features of mirrorless. And the camera does have it… but only when shooting video. Not useful when I need to shoot fast in changing light.

What I resort to is that I enable 2 second “Viewfinder review” with “Exposure Highlights,” or blinkies. Unfortunately, this means I can’t see anything after I shoot unless I tap the shutter button. It’s not a great workaround but it sort of works.