Working with old Victorian and early 20th Century barrel lenses is fun but these lenses are often used without a large format shutter on wood and brass style Field Cameras. Having no shutter is fine if the exposure is several seconds or more. Simply pop off the lens cap wait a bit and put it back. But what if the exposure you need is much less than a second ? or even a second and a half?
Once you have decided you need a shutter, the challenge with barrel lenses cameras, is where you will place the shutter in the path of the light to your film or plate? There are three possibilities:
- Before the lens.
- After the lens and before the bellows.
- After the bellows and before the film.
If you acquire a shutter for an old field camera it will most likely be a version of the Thornton Pickard (TP) roller blind designed normally to fit between the lens and the bellows. In some cases the slightly more sophisticated leaf shutters (eg. Packard) may be available. There is nothing wrong with TP roller blind shutters, but you generally need one in good working order sized for each lens and some barrel lenses are of a very large diameter and weight, creating a number of fitting issues.
Of course, if the shutter was between the bellows and the film it would be quite independent of your lens. This sounds great but a large format roller blind of this type is quite a beast, rare to find and complex to build. The place you’re least likely to think of putting a shutter is in front of the lens. However, it actually one of the simplest places to do it.
My Camera Shutter Build
I started work on creating a large format before the film Roller Blind Shutter, but its complex project and I needed something much sooner. I therefore decided to take a simple classic approach and create a gravity driven drop shutter to go in front of the lens. With a bit of careful design I planned to make it interchangeable across several lenses. I added a little electronics to extend its exposure time range.
Here is the result.
You can learn all about the shutter and see it in action in this video on my YouTube channel.