10d digital exposure compensations

A few questions....

1. Sounds like a stupid question but exactly what is the Canon eos

10d digital exposure compensation doing and how does it work?

2. If you have overexposed an image can you really restore detail

into burnt out highlights. And similarly can you use if to pull out

more information from underexposed shadows? Surely there must be

something you are sacraficing?

2. You have two versions of the same image: One that is correctly

exposed and one that was underexposed by a stop and a half and then

had a + stop and a half digital exposure compensation applied to it

on post. Will these photographs appear exactly the same or are there

disadvantages to the exposure compensation?

3. It has been talked about in this forum that for static shots

(landscapes, still life etc) you can take two or three shots at two

or three exposures and combine them in post to get an increased

dynamic range. If you are shooting portraits, repotage etc, I guess

you could use the exposure compensation to acheive a similar effect?

Thanks!

Hi Tim,

1) I can't tell you how it works in-camera, but can hopefully shed a little light - no pun intended. If you shoot the 10D in raw mode, you can adjust practically everything after the shot: exposure, up or down in 1/3 stop increments; contrast; sharpness; saturation; color temperature and I'm probably leaving something else out. This is non-destructive to the original raw file and the changes are only made to the resulting tif file it produces.

2) Digital cameras - and the 10D is no exception - are notorious for the ease in which you can blow out highlights. But so is slide film. They are very similar and relatively un-forgiving if you stray too far. It's my experience that with the 10D, it's best to underexpose a little and dredge detail out of the shadows than to blow out highlights. It's very difficult to get any data out of a badly-blown out (overexposed) part of a 10D image. (Not too bad at all with shadow detail) However, the camera has a histogram and if over-exposed, the image beside it will blink telling you so. Slide film won't do that.

2 Part Deux) Well in Canon's raw converter, you can kick the exposure up or down in 1/3 increments by as much as 2 stops, I think. However, this can only go so far if the image is badly under or over-exposed. Still, it's *very* valuable for salvaging a so-so shot. By the way, Ted Miranda sells a PS plugin (or action) that claims to reclaim detail from blown-out highlights, but I've not used it.

3) Yes. You could make your first tif file with low saturation and lots of sharpness and contrast, for example. The original raw file remains untouched. Then, you could make a second tif file with high saturation, low sharpness, and little contrast. And yes, you could register one over the other in Photoshop and play with it. I've heard the technique you describe used to help kick up the resolution of relatively low-res (3mp) cameras. Two shots of the same static subject are super-imposed on one another providing more pixels and detail. I've never tried the technique with any camera personally. Hope this helps! Best wishes . . .