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Sole Shooter
08-22-2007, 12:48 PM
Iím trying to understand how to use the histogram to better expose my shots. From reading the manual, I gather I want to keep the majority of the pixels right around the center vertical line (left = dark, right = bright)? Corrective action would go something like this; I take a photo, review the pictureís histogram then adjust via exposure compensation (- = darker, + = brighter) to get me closer to the center then reshoot photo w/ new EV and review histogram again? Anybody use flash exposure compensation in addition to (or instead of) exposure compensation? Also, what can be done about highlights to reduce their affect on exposure?

erichlund
08-22-2007, 01:31 PM
Iím trying to understand how to use the histogram to better expose my shots. From reading the manual, I gather I want to keep the majority of the pixels right around the center vertical line (left = dark, right = bright)? Corrective action would go something like this; I take a photo, review the pictureís histogram then adjust via exposure compensation (- = darker, + = brighter) to get me closer to the center then reshoot photo w/ new EV and review histogram again? Anybody use flash exposure compensation in addition to (or instead of) exposure compensation? Also, what can be done about highlights to reduce their affect on exposure?

Actually, you want to expose as far to the right as possible without going off the edge. Any part of the exposure that goes beyond the right edge is a blown highlight. Off the left edge is too dark. To minimize noise, you want as much light as you can get without blowing your highlights.

No Control
08-22-2007, 01:50 PM
It's really up to how you want your images to look. If you take an image and the histogram is bunched up to the right side but the image looks okay then there's no need to change it. "Correct exposure" is the exposure that creates the image as you want it to look. But yes, as erichlund said, the closer you can get the image to the right side without clipping the highlights is usually best.

fionndruinne
08-22-2007, 06:15 PM
Something I learned (only recently! Shame on me) regarding the use of exposure compensation: when a camera meters off something, it will interpret it as a balanced, brightish (18% gray, if I'm not mistaken) object. Pattern metering takes more of the photo into account than spot, but regardless, the camera doesn't know, usually, whether a very bright (or very dark) object is supposed to be very light or dark. Therefore the rest of the frame is often going to be excessively under- or over-exposed. Exposure comp is a way of telling the camera "this object metered off is supposed to be bright/dark". Crank the EV up in the + range when you're metering off a very bright object, and down when you're photographing something dark (like a black dog).

We already know that EV brightens or darkens a photo, but that's a little oversimplified. Using the pattern metering function nullifies this just a bit, but it's still useful and important to know. Try switching to spot, and use EV while photographing some dark and bright objects. The results are informative, and might even turn out better than pattern metering, because you have more control.

erichlund
08-22-2007, 07:00 PM
Actually, each manufacturer's meter will be a closely guarded secret, but the actual value will be somewhere in the neighborhood of 12-14%. That 18% number refers to the Kodak gray card, which was a standard devised for calibrating printing machinery for the publishing industry. If you search Thom Hogan's website, there's a well written article on the subject, but I haven't seen it in over a year, so I don't know if it's still there on his site.

fionndruinne
08-22-2007, 07:41 PM
Ah, thanks, Eric. I kinda thought my camera interpreted things a bit brighter than 18%.

Sole Shooter
08-23-2007, 10:15 PM
Thanks for the info. I'll have to experiment a bit more with different settings. On a somewhat a related note, does anyone know of any application perferably freeware that I can install on my PC to view my photo's histograms just as I would on my D80?

Thanks,

Rob