Reciprocity Correction and Development Expansion

John Irvine

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Joined
Sep 23, 2007
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110
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Central Virg
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4x5 Format
I got into a situation where the calculated exposure in subdued light put me into the range of reciprocity failure, 6 sec with TX 320 at ASA 200. Kodak says give it 25 sec exposure. No problem. I made two exposures and developed one at N+1 and one at N+2. Negatives look good and seem to have taken care of the problems I had in "Exposure in the woods" discussed here a couple of days ago. (Thanks everybody for the guidance).

Today I noticed that Kodak also says in addition to increasing the exposure, decrease the development about 15%. Since I am increasing the development to expand the tonal range, should I have left it at N+1 and N+2, or taken those numbers and decreased them 15%? Or would the negatives have not shown the difference.
 

CBG

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Nov 21, 2004
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Multi Format
If the negs look good - and presuming they print well - you probably nailed it - and I would guess the original scene deserved a bit of extra development to obtain a normal contrast range. If they are too contrasty, then maybe you did add a bit more development than desirable.

Ordinarily, reciprocity failure and extra exposure to correct do bump up the contrast and would suggest a slight reduction in development.

C
 

Claire Senft

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Dec 7, 2004
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3,239
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Milwaukee, W
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I agree with CBG, alway be ready to accept success. If you feel that the prints require a paper of lower than usual contrast then make a test next time.
 
OP
OP

John Irvine

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Joined
Sep 23, 2007
Messages
110
Location
Central Virg
Format
4x5 Format
I printed them both last night. N+2 took about 15% more exposure to get the same tone at the low end. There is not much difference between the prints. There may be a little loss of detail in a couple of the lightest spots in N+2. Looks like N+1 got the prize.
 
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