Archived posting to the Leica Users Group, 2001/01/09
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Let me go out on and limb also. Please check my math as the numbers on my
calculator seem to get smaller each year. 11X14 paper is 27.9 X35.6 cm in
size. To get an full frame enlargement from a 35mm negative you need to
enlarge 11.63 X (27.9/24). I suggest you need 4 lp/mm in the print for it to
seem sharp. I suggest you get a 80% transfer efficiency from the negative to
the print using normal enlargers and lens. You would then need 58.15 lp/mm
in the negative for a print to seem sharp. ( 4X11.63X1.25) I can only seem
to get this " sharpness" from Tech Pan. I have tried Agfa APX 25 but I can
clearly pick out the 35mm print from prints from larger formats. The Agfa
film is starting to show grain and loss of " sharpness" when enlarged 11.63
X.
I have also done this experiment with the smallest of medium format.
6X4.5 .To get a 11X14 print from this size you need to enlarge 6.2
(27.9/4.5). Using the above numbers, (4X6.2X1.25) you need 31 lp/mm. I find
that with this size negative and Agfa APX25 I can get a print that shows no
grain and appears "sharp "even with close inspection.
There are many issues in choosing a format for a picture situation. I
like Tri X with my 4X5 for landscapes. I also push Tri X to 1600 with my
Leica. Grain in these pictures just seems part of the photographic process.
I may have made some mistakes with my numbers and would like to be
corrected. Also I would like to know the experience of others in making fine
prints from Leica negatives. Bill