How one comment at a camera swap meet fixed my shutter timing for good

Some guy at the Portland Camera Swap Meet last month watched me test a shutter and said 'you're measuring the curtain travel not the sync speed.' He was right. I had been using a simple audio trigger but the numbers were off by about 3 milliseconds which threw off my flash work. Now I use a photodiode sensor with the oscilloscope and it's way more accurate. Has anyone else found a cheap way to test sync speeds without dropping cash on a proper shutter tester?

2 comments

2 Comments

rodriguez.cora29d ago

Have you tried using the built-in flash on a old film camera as a poor man's trigger? I set up a piece of white cardboard at an angle, put my phone in slow-mo video mode, and popped the flash while the shutter was open on my test camera. The difference in brightness between the first and second curtain shows up as a dark band on the video. I can measure the band width against the frame rate to get my sync speed within half a millisecond. It's janky but costs nothing if you already have a modern phone.

the_mia27d ago

Half a millisecond? That's wild. I've been doing the phone slow-mo trick too but I just eyeball the band and guess, honestly. The measuring thing makes way more sense, I never thought to actually calculate it that clean. My last attempt gave me like 1/125th on a camera that's supposed to sync at 1/60th, so I clearly need to steal your cardboard setup.