How to measure the speed of my antique shutter

My Boots branded 100 year old Thornton Pickard camera has a new addition – a mechanical shutter. This allows me to shoot at speeds under 1 second. With these faster speeds I can use 200 ISO sheet film instead of the much slower photo paper.

To measure the speed of this shutter, I fixed it in front of my digital fuji XT20. I set the Fuji on a 5 second exposure on f8 (as wide as the old camera goes). This gave me time after pressing the Fuji shutter to then trigger the old shutter.

I then viewed the histogram of the image taken – which was of course, at the speed of the old shutter.

I then moved the old shutter out of the way and took a few images on the Fuji adjusting the shutter speed until I found a speed that gave me a similar histogram to that obtained with the old shutter. This turned out to be a useful 1/30s.

The speed of the old shutter can be changed – but it is a bit of a fiddle.