Quote:
Originally Posted by raymo
Also remember that Paul's lens is more than a stop faster than mine was.
My 100mm f/2 shows a little colour at these short exposures; my zoom was operating at f/4.
raymo
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40mm focal length, 7 secs, f/4, ISO 12800, (effective aperture 10mm)
135mm focal length, 5 sec, f2.5, ISO 1600, (effective aperture 54mm)
I had considered the slower lens at f4 but also thought the difference in ISO and slightly longer exposure would have made a difference. Perhaps reciprocity failure also affects some digital sensors and not only film. However there is a big difference in effective aperture at the given f stops. Could this be the reason irrespective of the speed/f-stop/ISO triangle. (Correct me if I’m wrong here calculating this).