In many discussions or ads you read : this lens is sharper than....
I wonder how people come to this conclusion. Recently I doubted the sharpness of my 120mm/f6.8 Angulon a bit in the sense that a relative small enlargement (8x10) of a negative did not give me the sharpness I was expecting. So I decided to run a crude test to see if it was an operator error and not the 120 Angulon.
So I set up a little test scene in my back garden, with some garden furniture, mounted my 4x5 TechIII on a tripod and shot the scene on EFKE PL100 (not the sharpest film in my hands, but that does not matter, I use it for both lenses) at f16.
As a kind of bench mark I used my most modern lens a recently acquired 90mm/f8 SuperAngulon MC, also at f16. Moving in a bit closer to get the same scene on film (distance to the focusing point now about 2 meters).
Processed the negatives (shot at 50ASA) stand developed in PyrocatMC, put in my enlarger, as high as possible (for a 50*60 cm print). Made some prints (13*18 cm) from various parts of the scene (150 CompononS at f11).
Against my expectation the 120mm Angulon outperformed the 90SA, and yielded the sharpest/crispiest prints..
So much for a test. Drawbacks are: I should have shot more film, use another lens as a benchmark (the 90SA I recently obtained, but I did shoot a couple of 4X5 FP4 negatives which look under the focusing scope plenty sharp to me at 5* enlargement)
So how do you tackle such tests?
thanks,
Best,
Cor
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