On May 21, 2005, at 8:13 PM, Kenneth Waller wrote:
Paul, thanks for the explanation. A few questions tho -
If he were shooting jpegs, the camera probably
would have compensated with more brightness and a bit more exposure.
The camera compensate? You mean the photographer?
No, I mean the camera. When you shoot jpegs, the camera does some
processing of the image. That's why you have to set sharpness,
saturation, etc. Whey you shoot RAW, the camera leaves the data alone.
That's what I mean that the camera would have compensated if he had
been shooting jpegs. In other words, it would have responded
differently to that meter reading.
But since he was shooting RAW, the meter cut things off at the point
where
the highlights
wouldn't be clipped.
Do you really mean meter?
Yes, or the camera's firmware that makes decisions based on the meter.
I'm guessing now, but I think it probably runs a different exposure
program for RAW than it does for jpegs.
I guess the most important thing I got from your response was that the
histograms of the same scene, shot in Raw and JPEG will be different.
Thanks for the education
Kenneth Waller
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, May 20, 2005 3:23 PM
Subject: Re: Speaking of exposure....
Hi Ken,
In Don's image the whitest whites are very close to pure white and
approaching
overexposure. You can see them in the histogram as well. Because they
are
such a
minor part of the image, they're only represented by the narrow line
running
across the bottom. With more exposure they would have been off the
scale.
This
is a correct exposure for RAW. If he were shooting jpegs, the camera
probably
would have compensated with more brightness and a bit more exposure.
But
since
he was shooting RAW, the meter cut things off at the point where the
highlights
wouldn't be clipped. Of course the midtones are all pushed down in the
scale and
have to be brightened. But that's the nature of RAW images. They are
different
than jpegs. That's the point. They give the photographer control. The
first
priority with RAW is don't clip the highlights on exposure. The
midtones
will
frequently look underexposed. Don also needs to pull the shadows up a
bit
to get
them off the far left just a tad. Once the midtones are brightened
and the
shadows adjusted, the image will probably need some contrast tweaking
to
separate the highs and lows a bit. But the exposure is correct.
You can't really generalize about how a histogram should look
Agreed, I wasn't generalizing, I was talking specifically about his
histogram
and his image.
Don's exposure is pretty darn close for RAW
Don't know what that means. Either the exposure is right or it isn't.
His image
didn't appear to have the correct exposure as posted. His histogram
seemed to
agree with that. There were white shirts in the image and I assume
there
were
black features in there somewhere. I also assumed that he wanted the
whites
white and the blacks black. If the exposure was properly captured,
the
whites
should look white and the blacks should look black. I don't
understand
how the
capture mode (Raw, JPEG, Tiff etc) has anything to do with proper
exposure at
time of capture.
Can you educate me?
I'm teacheable, I think.....
Kenneth Waller
-----Original Message-----
From: [EMAIL PROTECTED]
Sent: May 20, 2005 2:08 PM
To: [email protected]
Subject: Re: Speaking of exposure....
You can't really generalize about how a histogram should look. If
there
are no
highlights or deep shadows in a scene, the values may very well be
bunched in
the middle. Don's exposure is pretty darn close for RAW. The
highlights
are just
showing good detail. They aren't grey. With digital RAW you have to
expose for
the highlights. I think the camera's metering scheme knows that. A
lot
of my RAW
images would appear to be underexposed at first glance, but when the
highlights
are evaluated independent of the rest of the image, it's obvious that
the
exposure is correct. RAW images are not meant to be viewed in an
unprocessed
state any more than is a negative.
Paul
All of the shots that night with 3 lenses were underexposed
by 1 or more stops.
Looks like you're on the right track with your observation.
Any ideas what went (or I did) wrong?
As you have described your captures, you should have added exposure
compensation
to you images in-camera.
This histogram needs the captured data to be spread across the
horizontal
axis,
not gathered as it is on the
LH side.
In PS, setting the white point and dark point will minimize the
color
cast.
Kenneth Waller
-----Original Message-----
From: Don Sanderson <[EMAIL PROTECTED]>
Subject: Speaking of exposure....
Here's one of the (rather crappy) shots from the play Wednesday
night:
http://www.donsauction.com/pdml/UnderExp.htm with histogram.
Forgive the composition, the girl in the middle is the neighbor.
(Had to shoot from the back, to short FL, yada yada, excuses.)
And the lovely mixed Tungsten/Fluorescent/Sodium lighting. :-(
This was at ISO1600 on the D with Matrix (CW with this lens)
metering. M200/4 at 4.
This is straight from RAW to web, full frame
All of the shots that night with 3 lenses were underexposed
by 1 or more stops. The other 2 lenses were FA's.
Had the LCD off as usual so I never looked at the histogram.
Any ideas what went (or I did) wrong?
Don
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