Shutter testerq

Jim Jones said:

The manufacturer's tolerance is immaterial. The photographer should establish his own margin of error for shutter speed, aperture, and processing variables.

Click to expand...

Yep. If you require 1/4 stop maximum tolerance, then that's the standard. If 1/3 is acceptable to you, that's the standard. If 1/2 works, that's the standard.

Jim Jones said:

The manufacturer's tolerance is immaterial. The photographer should establish his own margin of error for shutter speed, aperture, and processing variables.

Click to expand...

exactly.in my test charts,I flag any results out side+/- 1/6 stop.that's pretty tight tolerance and well within processing tolerances.in other words,it won't matter.

I'm an amateur in all this.. Photography, electronics and programming.

But I made my shuttertester from this diagram found on the net. As I'm mostly interested in rather old cameras, I find this tester is accurate enough.

To record and view results I use a simple bash-script which calls a simple awk-script (on Linux. Sorry for the comments and variable names being in Norwegian. If anyone is interested, please PM me, and I'll translate or explain.)

Output from the script is like this:
025.dat
0.0440s eller 1/22.7

I also made a timer based on an opto-transistor and the audio input on a soundcard. Looking at the shape of the waveform I improved the steepness of the gradient (and hence the ease of reading it) by making a slit, parallel to the edge of the focal plane shutter, with a couple of pieces of tape over the drilled round hole. The light therefore makes a more sudden change as the edge of the slit is uncovered, instead of a 'gradually' widening circular hole. This wouldn't be applicable for leaf shutters of course.

Uses an ordinary photocell. Timer automatically resets after each shutter actuation. n.nnnnn display measures shutter times from 8 secs to 1/8000.