Chris Barker wrote:
>Moose
>
>Looking at the IT8 target and at the differences between top and bottom
>(unadjusted and adjusted respectively?), it looks as the adjusted chart
>is not rendered properly; there are few graduations in darker tones. I
>shall have to assume that it is my monitor compared with yours.
>
As I said, probably in a couple of different posts: First, there is no
way to profile a monitor and second, that these images are just as they
came from the scan, with no adjustments other than downsizing.
Assuming I have my monitor properly calibrated to the rest of the
components, everything should look pretty much the same, but I'm not
sure I've done that. I recently had to change monitors and I'm not quite
happy I've got it right yet. One can, in any case, scan slightly lighter
across the board, if necessary, without losing the other attributes of
using the profile.
On my monitor, I can distinguish all but the last 2 blocks on the black
end of the bottom, profiled, image but the other end is not pure white.
the opposite is true of the top, where the white is pretty close to
pure, but the other end only goes to not very dark gray. I'm not sure
what it all means, but included the IT8 scans as a matter of interest
and in the way of being complete. In these images, there was no loss of
luminance info off the ends of the histogram. The White and Black point
settings still control that. It may be that the profile introduces a
curve that compresses the range at the ends and gives stronger contrast
in the mid range.
>But I use "lock image color" (sic ;-)) by scanning a blank frame from the
>start of the film and adjusting all my scans from there on.
>
I just tried that for the first time on the last roll I scanned. The
results were less than impressive, with a slight green cast to the
images. I suppose I did something wrong, but don't know what yet. In any
case, scanning a black frame can only make a custom adjustment for the
density and color of the film base. It can't adjust for color balance is
the same way a profile does.
>Is that simpler than the IT8 method or more complicated, in your view?
>
Once you have a profile for a particular film, use is much quicker and
simpler than the lock business. Making a profile is very quick, once you
have an image of the traget on film. Since the profile must include the
effect of the film base I'm not sure one needs both.
>Your adjusted shots show more contrast, so I suppose a "vulnerable"
>high tone is more likely to be blown out as a result of adjustment.
>
With 16 bit output and proper B/W point settings, nothing gets blown
out, in the sense of being lost entirely to pure black or white, but
clearly there is some compression. As you noticed in the target images,
it was shadow range that seemed compressed, not high tones. Also, I work
from RAW files, so it would be no big deal if I had to 'rescan' an
occasional image from the RAW file.
>Whatever the explanation, I prefer all the adjusted shots.
>
As do I. Results, more than theory, are why I like the process. My
straight scans of negatives with Vuescan always require adjustment.
Everything for a great image is captured, but looks flat. Of course, I
have much of that process automated for many for many kinds of image,
but it is still extra work. With the profile, many images don't require
any adjustment at all.
Moose
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