On 1/28/2012 6:29 PM, Paul Stenquist wrote:
You can "expose to the right" or anywhere you choose by using exposure comp in
any metering mode. The metering isn't based on jpeg or RAW. It's based on the light and
what's in front of the lens. No meter is smarter than a photographer who understands how
meters work.
I'm certain that if I'm wrong someone will correct me. The metering
mode in our cameras picks a spot to meter on, and sets the exposure for
that point at midpoint. This means that if you look at the histogram,
you usually get a bell curve right around the middle of the graph,
expose to the middle. This means that if you go direct from RAW to JPEG
without any compensation in post processing, most of the pixels in the
photo will be right around the midpoint of exposure.
What it does not do is look at the pixels out at the tail end of that
graph. If a bunch of them are off to the right, and you expose for the
middle, then you end up clipping on a lot of your readings, in other
words, you'll lose highlight detail.
Alternatively, if most of the readings are to the left of the point that
is metered for, then exposing for the middle will leave you with either
a lot of pixels that are clipped black, or a lot of your shadow detail
lost in the noise.
The principle of exposing to the right has nothing to do with where you
put the peak of that bell curve, but that you expose the picture as much
as you can without clipping details in the highlights. In the first
case, this will reduce the exposure on the fat point of the graph,
giving you a bit more noise, but you won't lose information in the
highlights.
In the second case, you expose everything a bit more, then when you
compensate in post production, the noise gets reduced along with
everything else, improving your signal to noise ratio. Not entirely
unlike how Dolby noise reduction works, apart from Dolby being on an
analog signal, and only in certain frequency ranges, but still, amplify
everything, signal and noise, and then when you reduce everything, the
noise is reduced.
Perhaps, I'm missing something, butI don't know what you men by choosing 18
percent gray for shooting jpegs. You can use the spot meter and take gray card
readings if you want a pure 18 percent gray exposure read. A histogram based on
the raw might be nice, but it's not hard to interpret a jpeg histogram in terms
of where you'll be with RAW. If you're edge to edge with jpeg, you're pretty
much golden with RAW, and if necessary, you can push it beyond that a bit.
Paul
On Jan 28, 2012, at 8:58 PM, Larry Colen wrote:
Never mind raw on a point and shoot, I want my DSLR to properly support shooting in raw.
I want metering and histograms based on the raw data. I want to choose metering modes so
I can use "expose to the right" for raw, and if I want to shoot jpeg I can
choose 18% grey, or whatever they call it.
For doing landscape and studio work, I fantasize about a mode that will take a
test shot (or three), examine the raw data and set the exposure for details in
the highlights or the shadows, or the bracketing for an HDR series of exposures
that will cover the full tonal range. I want a TAv mode for the green button
in M, so that I can set the shutter speed and aperture based on a critical
element of the photo, have it set the ISO, and then just leave it there.
Everything about using my camera indicates that raw is an afterthought, and the
UI is optimized for people that want a $1,000 point and shoot with
interchangeable lenses.
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Larry Colen l...@red4est.com (from dos4est)
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Larry Colen l...@red4est.com (from dos4est)
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