I am a huge fan of giant, fast lenses. From 135 (i.e., “35 mm”) to medium format and to large format, I go for the fastest lenses that produce the shallowest of DOFs.
However, the pursuit of fast lenses becomes a bit problematic with large format, where most lenses these days use leaf shutters mounted in or near the lens barrel. Because of the structure of leaf shutters, there is an upper limit in the shutter speed (the fastest I know of is a shutter that can do 1/1000s on a 4×5 Graflex Super Speed Graphic), which decreases the larger the shutter.
One of the largest leaf shutters you can get is an Ilex #5, which can be used with a lens barrel of around 75 mm in diameter, with a top speed of 1/50s. For example, this shutter can be used, with a little work, with the famous Kodak Aero-Ektar 178 mm F2.5 lens. But the 1/50s shutter speed is not ideal, precisely because of the fast nature of the lens––you really need faster speeds if you want to shoot wide open and not rely on neutral density filters.
Now, the Aero-Ektar (AE) is terrific in 4×5; but when it comes to 8×10 and larger, the big, fast lenses are simply too large to be fit on any leaf shutter. I.e., all of the fastest lenses for 8×10 and greater are barrel lenses, lacking a shutter mechanism. So what do people do when they want to shoot with them wide open?
One of several things. One can always use a very slow film in subdued lighting conditions, and utilize the lens cap shutter method. That is, take lens cap off to start exposure, put lens cap back on to end exposure.
There are Packard shutters, which can be used with giant lenses (up to 8”/20cm in diameter), but they are limited in the usable shutter speeds––namely, “timed” which is akin to the “T” setting on normal shutters, or in the case of their “instantaneous” shutters (No. 6), a single speed of around 1/25s.
The so-called “Jim Galli” shutter, which is basically using two dark slides and a slit in-between as the shutter mechanism. OK, watch the video to see what I mean:
The issue here is that it’s going to take a lot of practice to master the various “shutter speeds” and even then, I don’t know if I’d ever be proficient enough to rely on it for a crucial shot.
Then, there is the Graflex focal plane shutter (similar in structure to the Thornton-Pickard shutters, which are mounted immediately in front (or back) of the lens) for 8×10 cameras.
The structure of the shutter is pretty much identical to focal plane shutters you find in Graflex’s large format SLR cameras (e.g., R.B. Graflex Super D), just scaled up for 8×10, and designed to be mounted on the back of an 8×10 camera where the ground-glass back would normally go.
These shutters have four differently spaced apertures and six tension settings, allowing for 4 x 6 = 24 different shutter speed settings up to 1/1000s and as slow as 1/10s, as well as a “T” setting, and so are perfect for using with very fast barrel lenses. The problem is, they are extremely rare; not many were made, apparently, and they were all made during the early 20th century.
I’d been searching for one for sever years; I missed a couple on sale at Large Format Photography Forums, and missed a few on Ebay during the time, until finally, last month (February 2015), I was able to score one on the big auction site.
I paid a pretty penny for it, and overall it was in a pretty good condition for what is probably a 100-year old shutter, but the shutter cloth (or the rubber coating thereof) was dried, wrinkled, and had many small pinholes. It clearly needed a repair and a CLA (clean, lubricate, adjust). Incidentally, the shutter was designed for a different 8×10 camera, and will not fit the back of my Deardorff V8 camera. Several things need to happen before I can happily start shooting with this shutter. And they are all lined up…but that is for another post 🙂