Methods for testing unknown shutters?

[Memento Mori]

I have recently gotten my hands on 3 lenses for my Speed, and also tightened up my focal plane shutter…and now need to test the speeds on them. The faster speeds usually hold up well (from what I read) but the slower speeds…are suspect. For example only one of them has a 1sec setting that takes about a second to open and close. I would ideally like to test all the speeds so I know what I’m dealing with before I waste too much film.
My plan was to set up a still life with lights and take careful notes while running thru lots of film. This, while setting up my digicam next to it to match settings for comparison.
A lot of work and film!
Edit: just found this…anybody have one, use one, recommend it?
https://www.catlabs.info/product/pho...r-speed-tester

[Bill Burk]

You can get apps for your phone that listen to the microphone and graph the click bzzzz clack and the time between can easily indicate 1 second to 1/10 second accuracy.

In case you want to find the accuracy of the higher speeds, you have a lot of factors that mess with your reality.

With a leaf shutter you will need to test at the open and small apertures (they will have different exposure performance).

A densitometer and sensitometer and gray card are your friend here. In addition to a sensitometer exposure that you graph, you can make test exposures of a gray card with the camera set exactly to the meter readings. For the purpose of hitting exactly, I have 0.1 and 0.2 ND No.96 gelatin filters that I put over the camera lens.

Then you read the densitometry of the different test exposures which should fall on the graph at 10X the exposure of the speed point. (1.0 LogE to the right on the graph).

Any deviation in exposure can be measured on the graph and either corrected by adjusting the shutter or noted for the field.

[Memento Mori]

Thanks!

[Oslolens]

I have recently gotten my hands on 3 lenses for my Speed, and also tightened up my focal plane shutter…and now need to test the speeds on them.
Edit: just found this…anybody have one, use one, recommend it?
https://www.catlabs.info/product/pho...r-speed-tester

I'm using that one. Without the plug, I would not trust the result. The plug is small, so you can compare the top and bottom of your speed.

The film itself is less concerned about the normal hysteresis of + or - 30%.

I sold a Tessar 180mm with a shutter where 1/60 seconds could not be trusted. It is still in use.

Sent fra min SM-S901B via Tapatalk

[maltfalc]

just stick your digicam behind the shutter, take a photo through the open shutter at say 1/30s then a second photo in bulb mode while tripping the shutter at 1/30s.

[Tin Can]

I listen

I trust my ears

Specs are plus minus 30%

[Memento Mori]

Good idea, thanks

[Memento Mori]

Yes well I’ve got 4 shutters and a focal plane shutter that are all slightly different. I want to know. Film and time are important. Plus, I’m shooting a lot of portraits, which are hard enough to set up, without mystery settings.
Glad your method works for you.

[paulbarden]

I've used this for 3 years and it works perfectly: https://apps.apple.com/us/app/shutter-speed/id560154244

[lassethomas]

I've used this for 3 years and it works perfectly: https://apps.apple.com/us/app/shutter-speed/id560154244

Me too, with the additional plug. Without the plug shorter times are hard to measure.
Much better than nothing.