| Author | Message | ||
     rick oleson Rating: N/A |
High speeds are off on leaf shutters, almost by definition: Since the shutter blades open from the center out, and at the highest speed they are in constant motion, the center of the lens gets a much longer exposure than the edges. Ideally, the shutter should be timed to give the light-transmittance equivalent of the marked speed, but even this is impossible as it will be different at different apertures. A shutter passing 1/500 second worth of light at f/3.5 will be passing about 1/250 second at f/16, and may read as 1/250 on a shutter tester at either setting (depending as much on the design of the tester as on the accuracy of the shutter). I don't even bother testing high leaf shutter speeds on a tester; the only reliable test is a roll of film.  = |