> With slide film it's a good idea to get the exposure right. > But if you are going to err, err on the side of underexposure. > There's nothing you can do about a blown-out highlight, but > you *can* extract detail from overly-dark areas at the cost > of lower signal-to-noise ratio.
I'm amazed at what I've been able to pull out of (somewhat deliberately) underexposed Velvia slides after scanning them. How they did it before the negative scanner I'm not sure. You can get some neat pastel effects by deliberatly overexposing the right slide film, but it's not what most folks are looking for. > Negative film has a lot more latitude to start with. But > it usually has more latitude for overexposure, so that's the > way to go if you're not sure. A lot of people recommend overexposing print film by up to a stop as a matter of course. I'm not sure I'd recommend that, but everything I've read suggests that it tolerates overexposure much better than underexposure. Color negative film looks nasty underexposed. As to digital, I'm curious. It DOES behave more like slide film than print film in that it has less exposure latitude and overexposed highlights blow out easily. Underexposure can be amazingly well finessed in photoshop, to the point that a lot of pros are saying that you "gain a stop with digital" because you can deliberately underexpose by a stop and still get a good image out of it in post-processing. Question is, why is underexposure easier to handle? Presumably white is represented by some number, say 255, and black by 0. You'd think exposure would fall off either end just as easily. Does it have to do with an exponential response curve of some sort like film has? Sort of Tri-X like in the toe and T-max like at the top... DJE
