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[OM] Color correcting concert photography

Subject: [OM] Color correcting concert photography
From: "Jim L'Hommedieu" <lamadoo@xxxxxxxx>
Date: Mon, 2 Dec 2002 07:12:31 -0500
This is exclusively about color correcting Fuji Supra 800, shot without a
blue filter under tungsten, concert light.

The manual for my Minolta Dual Scan II film scanner is not well written to
begin with and is not very well translated into American English either.
After scanning for weeks, I found the pre-scan histograms for  _individual_
channels (RGB) in the "Utility" software.  From looking at all 3 histograms
at once, it was obvious that the red channel had a much different highlight
area from the other two channels.

On a hunch, I first adjusted  just the highlight point of the red, (whatever
you call the "toe" at the highlight end of the histogram), then used the
preview image to dial-in the midtone of the just the red channel.  Bingo.

>From my notes,
"leave the green and blue histos untouched
(G: 0 shadow;  1.00 midtone;  255 highlight
B: 0 shadow;  1.00 midtone;  255 highlight)
and merely adjust the Red to
216 for red highlight first, then 1.29 for the red midtone."

In my opinion, this is the most effective way to color correct.  It makes
sense to me.  It's exactly like setting the white point on a digital.
Everyone of my images includes some specular highlight from eyeglasses or
guitar strings or chrome plating on an amp.  Something.  The histograms show
exactly where the white point is for each channel.  It's child's play to
tweak one channel, once you find the right window.

The other methods I tried, like making straight scans and doing the color
balance in the editing software, gave weird results like a perfectly
adjusted midtone but a shifted highlight.  (I had some frames that I had lit
with an Olympus T32 flash.  After I had perfected the skintone, the white
pine paneling still registered cyan and slightly blue.  Does everyone's T32
give +15 cyan and +10 blue light?)

Besides being most effective, this method of adjusting setpoints before
scanning is very simple and quick.  You don't have to wait for your editing
software to recalculate the color of every pixel of a 2820 dpi frame, for
example.  Not that I'm recommending it because it's quick.  I'm recommending
it because it produces the finest result on my particular scanner and Adobe
Photoshop Elements Version 1.  Your mileage may vary especially because (I
believe) Elements, Version 1 is hobbled into 8 bits per channel.

Gees, I'm long winded tonight.  Did anybody read this far?  :)  Gees, I'm
glad to have a computer and scanner.  Now I can custom print and retouch
color photos at home!  How cool is that?

Lama

Now playing: Thelonious Monk's "Brilliant Corners"   If you like music that
helps you think, Monk's your guy.


From: "R. Jackson" <jackson.robert.r@xxxxxxxxx> said,
> I'm not an expert on darkroom technique by any stretch of the
> imagination, but I'm pretty sure it means that the contrast in the
> various layers of the film emulsion aren't analogous to each other. In
> this case he's saying that the blue layer may not be exposed properly
> unless you slightly overexpose and that trying to make a print where
> the contrast of one layer doesn't match the others will produce
> unwelcome artifacts.


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