super symmar XL 110 (shutter speed) : LUSENET : Large format photography : One Thread

Does shutter speed vary continuosly from 1 sec. to 1/400th sec. Or, do the speeds change discreetly from click to click (number to number)?

-- Jon Miller (, May 09, 2000


This a function of the shutter, not the lens. Most likely, you have a Copal shutter. They are only supposed to be used on the discrete click stops, so you can only vary the speeds in one-stop steps.

-- Michael Briggs (, May 09, 2000.

Neither Copal nor Compur mechanical shutters allow repeatable intermediate settings. There is an internal cam arrangement in the form of a ring with a number of steps in it like this ___/ . At each step internal gear train positions and/or spring tensions are changed to give the required open to close delay time. If you catch the cam halfway up the slope of the step, there's a chance that you'll get an intermediate speed, there's also a chance that you'll get a cog half-engaged and get an entirely wrong speed while grinding the teeth of the gear.

-- Pete Andrews (, May 09, 2000.

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