Shadows/Highlights question

[Bob32]

I am using PSE 4 for Mac. When I edit underexposed photos using Shadows/Highlights I move the Lighten shadows slider in increments of 10%. How many f-stops or fraction of an f-stop is represented by each 10% increment? I'd like to know so that I can estimate how much I have underexposed each photo.

Bob

[Rusty]

Bob,

Somebody a lot smarter than I may know how you can do that. I don't think it works that way.

A better approach would be to review the histogram. Even then, I don't think it relates to specific f stops. An even better approach would be to review the histogram when taking the pictures if your camera provides that ability. You will know immediately if you are over/under exposed and can reshoot.

Rusty

[JulieM]

Bob: Welcome! Just to add to Rusty's comment, a tool which might be of use to you in determining your over/underexposure in relation to f-stops might be Adobe Camera RAW. It's exposure slider allows you to adjust your exposure in by f-stops. If you don't already have ACR 4.1, you can download here (http://www.adobe.com/products/photoshop/cameraraw.html).
You can use it with PSE4 and while it is obviously an editor meant for images shot in the RAW format, it can be used with JPGs.

[Bob32]

Rusty,

I just started the procedure of checking the histogram and adjusting the exposure when the histogram is not far enough to the right, but so far I find it to be trial and error to determine how much to adjust the dexposure to move it a given distance. Perhaps in time I will get a feel for it.

Bob

[Rusty]

Bob,

For a lot of images I will find myself using an EV adjustment to deliberately underexpose the shot if there are parts with strong highlights.

Elements can't fix blown highlights because "there's nothing there". It does a great job pulling detail out of underexposed sections.

There is a lot of trial and error to my method - I'm nowhere good enough to simply look and know what to do. If it's a shot where I have the time, I'll put it in Program mode and "let Nikon drive". As I change the settings with the wheel, f-stop and aperture move in tandem. I take that shot.

Then I dial in an EV setting of -1.00 and take another shot and then -2.00 and take a third.

Obviously, this is not for fast action situations :)

Rusty

[ljameso1]

I just started the procedure of checking the histogram and adjusting the exposure when the histogram is not far enough to the right, but so far I find it to be trial and error to determine how much to adjust the dexposure to move it a given distance. Perhaps in time I will get a feel for it.

Bob, Just a couple exposure tips that may find useful. Metering something white and have detail is +1&1/2-+2 above what the camera meter tells you and yellow is about +1. Something dark brown to black would be -1/2 to -1. If there isn't a large enough area of what you want to expose can meter off something neutral such as green grass/trees, medium brown side or gasp a gray card and adjust exposure the opposite direction to what you would do if were able to meter directly on the most importsnt element. Still check histogram to tweak but, this will get you very close and you will gradually get a feel for how much adjusting to do for your individual camera's meter(they can become less accurate with age both digital and film camera meters.)

[Bob32]

Lindaj,

Thanks for the tips which reminded me of the fact that many years ago I carried around an old Weston Master III exposure meter that I used to take meter readings off the back of my hand. That was more convenient than having to carry a gray card! Since joining the digital revolution three months ago I have not heard a word about using the in-camera meter to take such readings, but maybe I ought to check it out to see how it works.

Actually the matrix meter mode on my D200 generally works great although it has a tendency to underexpose which is OK by me. Better underexposure than overexposure.! So far, when using unadjusted metering, the D200 has not given me a single overexposed photo. May the good results continue.

Bob