Over the past couple days I have tested all the shutters I own using a photovoltaic cell and my digital storage scope. The scope is a very accurate time base and captures a time v.s. light intensity trace.

I was shocked at the results!

Even in my best, recently services shutter showed speed errors of up to 25% at the high speeds. Some shutters had errors up to 50% !!!!

Of the 5 shutters I tested, all were consistent in their speed and varied less than 5% from one exposure to the next. Shutters with low speeds (slower than 1/5 Second) usually were the most accurate at slow speeds.

I was surprised (and somewhat appauled) to find shutter speeds were so much different than the set speed, even on the recently serviced shutter. My faith in mechanical shutters has been shaken! I look forward to getting the Compur electronic to see if it is more accurate.

Has anybody else tested a number of shutters? If so, what were the results?

I did note the set speed v.s. the actual speed in my notebook for each shutter. Maybe I should put this info on a sticky label and attach it to each lens board.....