Histogram/ exposure: Help

[Cutter]

Can someone help me! Say i have taken potrait picture with a dark background, and the face and hair, When looking at the histogram and it shows that the blacks are clipped( which I want and expect) but the whites are say 1/4 off from being clipped does that mean i should through more light on the subject until just before clipping to make the face properly exposed ? Hope this makes sense

[SieSmith]

What do you want it to look like?

[GeoffWessex]

With a Black background you can expect most of the pixels to be on the left of the histogram, and you are bound to get some clipped shadows in any folds, wrinkles etc of the background. It's not a really bad thing.

The only important part is the face - and you could have a dark-toned skin and shadows or a face that's just too bright. You should concentrate on the tones of the face and ignore other things. If your adjustments are making the background start to look grey you've probably gone too far..... so perhaps treat the background and face differently, by selection and mask, rather that adjust the whole image at a time. I prefer to see some shaping and shadows on the face - and certainly don't want any white, shiny areas - so I'd fully hope, and expect, to see the right edge of the histogram not reaching the ends. There again, teeth and the whites of the eyes - while not wanting them to be completely white - should make a few 'bumps' on the right end of the histogram. Keep an eye on the histogram not just in camera, but all through 'development'.

[Cutter]

Originally Posted by SieSmith

What do you want it to look like?

I want a black background but a perfectly exposed face. I supose that perfect exposure is whats inside my head!!! is that what your getting at ?

[Cutter]

Originally Posted by GeoffWessex

With a Black background you can expect most of the pixels to be on the left of the histogram, and you are bound to get some clipped shadows in any folds, wrinkles etc of the background. It's not a really bad thing.

The only important part is the face - and you could have a dark-toned skin and shadows or a face that's just too bright. You should concentrate on the tones of the face and ignore other things. If your adjustments are making the background start to look grey you've probably gone too far..... so perhaps treat the background and face differently, by selection and mask, rather that adjust the whole image at a time. I prefer to see some shaping and shadows on the face - and certainly don't want any white, shiny areas - so I'd fully hope, and expect, to see the right edge of the histogram not reaching the ends. There again, teeth and the whites of the eyes - while not wanting them to be completely white - should make a few 'bumps' on the right end of the histogram. Keep an eye on the histogram not just in camera, but all through 'development'.

Thanks for the info geoff, I guess what I am saying is should I be trying to get the histogram almost to the right to get a better exposure ? or does it not matter?

[GeoffWessex]

No, I think you can read too much into the histogram. Sure, you don't really want clipping at either end, but a portrait (IMHO) usually works better when it's a warm image - and the only bright pixels might be the teeth and white of the eyes - and even they just need to be relatively bright. The histogram in that case (with a really dark background) would be mainly on the left, may include some clipping and with a gentle slope towards the right (and a bump or two indicating the brighter pixels, giving it a nice balance). If you shoot in Raw you can push a little light back into the darkest areas with Fill Light and you can also 'turn down' the Blacks slider if you want to get rid of the clipping.

We don't take histograms - we take pictures. They either work or they don't.

[OldBoy]

Originally Posted by Cutter

Can someone help me! Say i have taken potrait picture with a dark background, and the face and hair, When looking at the histogram and it shows that the blacks are clipped( which I want and expect) but the whites are say 1/4 off from being clipped does that mean i should through more light on the subject until just before clipping to make the face properly exposed ? Hope this makes sense

A Histogram is only a guide to how the exposure you selected works. You can take a couple of shots where the Histogram looks completely different on each but the photos are perfectly exposed for the subject.

[Cutter]

Originally Posted by GeoffWessex

No, I think you can read too much into the histogram. Sure, you don't really want clipping at either end, but a portrait (IMHO) usually works better when it's a warm image - and the only bright pixels might be the teeth and white of the eyes - and even they just need to be relatively bright. The histogram in that case (with a really dark background) would be mainly on the left, may include some clipping and with a gentle slope towards the right (and a bump or two indicating the brighter pixels, giving it a nice balance). If you shoot in Raw you can push a little light back into the darkest areas with Fill Light and you can also 'turn down' the Blacks slider if you want to get rid of the clipping.

We don't take histograms - we take pictures. They either work or they don't.

so if we took a light meter reading on the face we should trust that and tweak it eitherway to suit our needs afterwards?

[silversnapper1]

Originally Posted by Cutter

so if we took a light meter reading on the face we should trust that and tweak it eitherway to suit our needs afterwards?

I've not had any experience of this type of photography Mark, but I know that there are some good (free) podcasts on apple itunes for the ipod. If you take a look at the Lastolite series with Mark Cleghorn, he uses backgrounds and goes through the metering very thoroughly.

[SieSmith]

Originally Posted by Cutter

I want a black background but a perfectly exposed face. I supose that perfect exposure is whats inside my head!!! is that what your getting at ?

Exactly!

Although I am guessing that with a black background you're not going for a high key effect.
So, like Geoff said, a small number of pixels to the right, unless there's something obviously white there, like a hairband or bridal headress for example.

Cheers, Sie