Photographic Control Spiral

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Timberwolf

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Apr 19, 2022
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Help me Mr. Wizard!
 
Joined
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Mr. Wizard! That takes me back.

As for the spiral (and in response to those who don't seem to understand it). It's just a graphic representation of the tone-reproduction matrix we see so often with the opposing H&D curves (one for the negative, one for the paper).

Once around the spiral gets you a lot of results. Then you start another, closer to optimal, trip around the spiral: Do you need to change your starting point (E.I.)? If so change that and move on to the next quadrant. Do you need to change negative contrast? If so, change that and move on to the next quadrant. Do you need to better evaluate your test strips to find a highlight density that works for base print exposure? Do that too and then go on to the print-contrast quadrant.

If you're still not happy with your prints, make another loop or two around the spiral.

Best,

Doremus
 

BrianShaw

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LOL… I didn’t really feel motivated so just went away until now. It is fascinating to see how the thread evolved.
 
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pentaxuser

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Well, Brian from what might be described as hostile "stony ground" beginnings it has reached 54 posts with now some substance and life. Nothing really gets dead and buried on Photrio not even Koda...something. Is this one of its strengths or weaknesses or often both?

pentaxuser
 
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