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Robert Sfeir |
9:12 26 Apr 04 |
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Robert Sfeir |
9:13 26 Apr 04 |
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Phil Davis |
7:15 27 Apr 04 |
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Robert S. Sfeir |
15:00 11 Apr 04 |
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Jorge Gasteazoro |
23:21 11 Apr 04 |
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Robert S. Sfeir |
5:07 12 Apr 04 |
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Phil Davis |
17:09 12 Apr 04 |
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Robert S. Sfeir |
17:34 12 Apr 04 |
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Jorge Gasteazoro |
18:39 12 Apr 04 |
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Re: Test Subjects at Home |
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Phil Davis |
8:55 13 Apr 04 |
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Robert --
I'm still worried about your bellows extension measurements. If you're actually using a 320mm lens (almost 13 inches) you'd have to have a total bellows length of about 25 inches (lens-to-film) in order to produce a sharp, life-size image. If you're telling Expo/Dev that the focal length is 320mm and the bellows length is 12-14 inches, the program figures that you're focused at infinity and the bellows factor it uses will be "1."
As a quick check, compare the total bellows length with the lens-to-subject distance. If they're the same then you are working at 1:1 and the factor is 4x. But if that's the case either your lens focal length is not 320mm or your bellows "extension" measurement of
"12-14 inches" is wrong.
There are now two instructional programs related to incident metering: one is "BTZS Lite" which is a collection of pdf files describing how to use BTZS metering methods with Expo/Dev without having to do the materials tests yourself; the other is a short video demonstrating incident meter use in a variety of subject conditions. Both of these items are available from the View Camera Store. I think BTZS Lite might be most useful to you because it explains how incident metering works. The movie shows some of those principles in action.
As far as metering methods go, you should be able to deal with your orchid closeups with either incident or spot rezdings, but my personal preference is incident.
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