This "regular" Technical Pan film will go up to 800 ln/mm
Development in a low contrast document developer.
Then the print paper, 100 ln/mm, and the optics of enlargement
Originally Posted by Fotohuis
all taking additively their toll.
LOW contrast DOCUMENT developer? Dan
Yes, like Rollei Low Contrast (RLC), Technidol, SPUR Technospeed, Moersch UGI, or a high Rodinal dilution (1+150 or more).
LOW contrast DOCUMENT developer?
Comparing film resolution figures:
We are generally looking at the highest resolution figures, those for high contrast subjects, as we are assuming that those figures corresponding to low contrast subjects will be proportional in value.
Or in other words: comparing films with different high contrast resolution figures, we expect that the one with the highest figure will also yield the highest figure for low contrast subjects.
I guess this will be the case for most common films. However this does not necessarily be the case, especially not with speciality films!
Thus we should have both figures in mind.
As pointed out early in the thread, the resolution you see in a photograph is a combination of the lens and film resolutions. With any decently high resolution film, you will continue to see improvements in the image as the lens resolution gets better, even if the lens resolution is quite far above the film resolution. That assumes all other factors are equal. There are several factors that affect resolution that make most of these discussions meaningless: resolution changes across the field of the lens; resolution is affected by film flatness and alignment of the image plane; resolution for a given lens changes with the wavelength of the light; resolution can change with temperature because of changes in the lens alignment; motion (even less than a wavelength); resolution changes depending on the location of the principal planes of focus; etc. In fact, it is just about impossible to design a lens with a reliable resolution of 500 lppmm. Very high resolution lenses are generally designed for a controlled environment at a single wavelength, with narrow fields, and at fixed focus points.
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I can appreciate the comments to the effect that lens contrast should be detectable. I found some old tests from Amateur Photographer magazine where T-max 100 developed in Acutol was used.Resolution at f 5.6 for high and low contrast targets was:
Canon EF 50mm f 1.8 127 lppm, 80 lppm
Zeiss Planar 50mm f 1.7 129 lppm, 92 lppm
Evidently the film can detect the better low contrast detail from the Zeiss lens but cannot detect any difference in the high contrast detail.