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Steve Nicholls |
0:02 16 Nov 05 |
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Larry Francis |
8:54 12 Oct 05 |
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Re: Normal SBR of 8.0 = dev time of... |
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Phil Davis |
16:39 12 Oct 05 |
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Larry --
"Shouldn't" isn't the right term because you can define your own "normal" development time.
The G=0.62 benchmark relates (approximately) only to the manufacturers' ISO film speed calibration (as defined by the ANSI/ISO Standard) and is rarely "normal" in ordinary practice, because (assuming a 7-stop SBR to be the practical norm for "ideal" subject conditions) it would require you to print on ES=1.3 paper (soft grade 1) paper.
If you're printing on "normal" (grade 2) paper (ES=1.05, more or less) your "normal" development (7-stop SBR) is around G=0.5 -- 1.05/2.1=0.5. None of this includes compensation for flare which would increase the G somewhat, but 0.62 is overkill for most pictorial photography with conventional materials.
My suggestion: Determine what you consider to be "normal" negative contrast for your general work, then adjust the developer dilution to arrive at that average gradient in what you consider to be a convenient time. I like 8 minutes because it's long enough to provide consistency and allow for precise time control without being unbearably boring.
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Larry Francis |
6:13 13 Oct 05 |
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Phil Davis |
6:52 13 Oct 05 |
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John Hannon |
17:30 8 Oct 05 |
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Phil Davis |
11:11 9 Oct 05 |
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John Hannon |
13:43 9 Oct 05 |
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Jorge Gasteazoro |
16:36 22 Sep 05 |
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Phil Davis |
17:57 22 Sep 05 |
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