Monday, January 15, 2007

Foma 200


Since Kurt is using Foma 200, and I like this film, too, and have some on hand, I finally made time to test it in the new version of Hypercat. Despite Kurt's report of thin negs at 5:30, my test results show 5:00 is about right for printing on a middle grade of paper with an Exposure Scale of 1.15, or about Grade 1 1/2-2. I haven't verified these results in the field, so consider this a starting point for personal testing. For those unfamiliar with BTZS data, SBR refers to Subject Brightness Range, and 7 correlates to a normal scene. Average Gradient is a measure of contrast, like CI, and EFS is Effective Film Speed. ES stands for Exposure Scale and represents the contrast/grade of the paper. Grade 2 papers typically have an ES ranging from .95-1.15, so 1.15 is on the border between grades 1 and 2. This data is consistent with printing using a diffuse light source, as in a cold light or dichroic color head, or contact printing. The use of a condenser enlarger would require a lower contrast negative to print on the same ES/grade of paper.

This data suggests ther isn't much room for contraction development by reducing development time, and reducing agitation might result in streaking, so a more dilute working solution would probably be most practical, or perhaps reduced carbonate concentration. I'll try both, eventually.

Film: Foma 200
Format: 120
EI: 200
Dilution: 1:10:300
Volume: 500ml
time: 5:00
Temp: 70F
Agitation: 0:10/1:00

4 comments:

kmag said...

Hello Jay,
Thank you for the test results. That helps to narrow things down to my camera or the light meter. I will try again with another. I am also going to print some of the negatives on Thursday, I might be surprised to find the negatives are not as thin as I thought.
Thank you for all the work you do.
Kurt

peter said...

Hello jay,
Just a question about the HYPERCAT formula -is the sodium carbonate anhydrous?
Would 200g of household sodium carbonate be just as good?
Love your photographs by the way-they are a very beautiful and tender.
Peter

jdef said...

Hi Peter.

Thank you for your kind comments. Household sodium carbonate is perfectly adequate. I often use pH Plus, intended for swimming pools, purchased at Walmart. Good luck, and thanks again.

Jay

Audiobookman said...

Thanks for all the great info,
I will be making some 16x20 negs
(portraits) from aphs with hypercat
Rated at about iso 4
Any advice/suggestions
Thanks