I've made two tests using one of my recently acquired cameras (Fujica ST801 with EBC Fujinon 1.8/55) on the resolving power of the lens. For the first test I used a moderate resolution film (Fomapan 200) and the results showed actually the resolution of the film (110 lp/mm) and not lens. Today I made new tests using Delta 100 developed in Rodinal 1:25. For the illumination of the test chart I used a 1000W halogen lamp, so contrast was high. These are my results (lp/mm) Aperture: centre, very close to edge, edge f1.8: 85, 57, under 50 f2.8: 156, 69, under 50 f4: 161, 89, under 50 f5.6: 147, 101, 55 f8: 115, 101, 69 f11: 69, 55, 69 f16: 69, 69, 69 Do you think I was doing something wrong during this test or it is actually possible to achieve such a high resolution with this setup? The lens is a 'Planar' type design.The prints from this camera do look very sharp (to me), even heavily cropped ones taken at f1.8. I'm somewhat surprised. :rolleyes: It also is somewhat interesting for me (I used a Tessar lens for a long time), that diffraction already takes its toll at f5.6-f8, most notably at f11.