Help with Histogram

[OscarWilde]

Can anyone on here teach me a bit about the histogram on a camera? I know how to access it; I've just never really understood how it works or what it achieves.

But I'm interested in learning! I know you can correct (or learn to see) blown out highlights and such with it and learn to correct them as a result, which is something I'd like to do more of!

So just wondering what kind of things one can "see" by looking at a histogram!

 

[Overread15 3]

Reading Histograms-- Part I
Histograms - Part II

Those two articles should give you a very good starting point

 

[480sparky39 38]

Histograms are basically pixel counts.

It's a chart that shows you how many dark & light pixels in the image.

The left side represents pure black, the right side pure white. The part of the graph on the left represents the darker areas of the image, on the right is the brighter areas of the picture. Ideally, there should be no, or few, pixels at the two extremes (unless you intentionally want pure plack or pure white).

 

[Big Mike]

Understanding Histograms

Expose Right

 

[OscarWilde]

Thanks! Read all 4 articles! (The exposing right one is an interesting practice!)

Thus the point of HDR photography is to take a photo and move the majority of the dynamic range to the left and to the right by over exposing one shot, under exposing one shot and accurately exposing the third! Resulting in a wide range on the histogram (or high dynamic range.... )

Don't you just love it when switches are flipped in your brain and suddenly understanding one thing fills in blanks in other places

Thanks again! <3

 

[Big Mike]

Thus the point of HDR photography is to take a photo and move the majority of the dynamic range to the left and to the right by over exposing one shot, under exposing one shot and accurately exposing the third! Resulting in a wide range on the histogram (or high dynamic range.... )

HRD would be used when your scene has such a wide range, that it would be off the ends of your histogram (if you exposed in the middle).

Consider the range of your camera's histogram (left to right), as your camera's dynamic range. Anything too dark will show as piled up on the left and anything too bright will show as piled up on the right. (and will show up as pure black or pure white (no detail) in the image).
So when your scene has a range that is greater than what your camera can capture (which is fairly common), you could take multiple shots, adjusting the exposure so that in at least one of the shots, the darkest areas aren't piled up on the left...and at least one where the brightest areas aren't piled up on the right. Then you use the software to combine the images for an image with High Dynamic Range.