Dumb question of the day, is there a way to measure the relative difference of light in an image in fstops?
Take this photo, is there a way to tell how many stops darker the shadows are compared to the climber?
I know the White Balance selector is Lr gives RGB%'s but that isn't much use. I am looking for a more mechanical system.
If it's your picture and you have the chance, take several pictures using the entire aperture range (f2, f2.8, f4, ..).
At home you can check the highlights and shadows for details and count the aperture steps in between.
Let's take the OP picture as an example. You should have some detail in the dark part on the bottom right or in the corner on the bottom left. Let's say you have that detail in your f2 shot.
The highlights should have details on the snowy part in the middle. You have that detail when shooting f11.
If you count the aperture steps in between, you know the contrast of your image in f stops, 6 in that case.
I hope that made any sense and is what you are looking for. It's a pain in the ass, but the only way I can think of at the moment.
>is there a way to measure the relative difference of light in an image in fstops?
Literally "zone system". There is an nice explanation on how it works on "way beyond monochrome" by Ralph Lambert, I think.
Also, silver efex plugin has separations by zones, very useful.