I found out last night after trying it and then reading about it that my modern flashes (modern meaning anything made past the 60s when Nikon introduced the first electronic flashes) will not expose the image correctly on my Graflex Pacemaker Speed Graphic.

What does this mean? Read on.

Rear focal plane shutters and in-lens shutters

Unlike many other large format cameras my Pacemaker Speed Graphic (let's just call it the Pacemaker for short now) has a rear focal-plane shutter. The shutter is in the body rather than in the lens. When you hit the release, a shutter opens, exposes light to the film, and then closes. If you have a camera where the lenses usually have the shutter, the camera is just a big open box and the way light is exposed to film is that a shutter opens in the lens.

The advantage of having a rear focal plane shutter is that you can mount very primitive simple lenses on it. For example, a lens with just glass; no shutter, no nothing. Since David Burnett photographed the Gore-Bush election campaign in 2000 with a Pacemaker and mounted an ancient WWII bomber observation lens on it (the now famed Aero Ektar) there has been a run on lenses that were basically tubes with glass in them -- ones that previously were moldering away in closets and attics as antique pieces.

Many of these have unique qualities and characteristics. This is as if someone in the paint world had discovered a new brush and medium.

So why is that a problem in this case?

Speed of focal plane shutter and electronic flashes

In prehistoric days of all mechanical cameras such as the Pacemaker did indeed use flashes. Picture the old 1930-1950s newspaper photographers with the big box cameras. When they took pictures of gangsters doing the perp walk they had these flashes mounted in front of parabolic mirrors. After each shot they would take the flash bulb and then chuck it. Not very environmental I know but that was because these bulbs were single-use.

One thing you may also remember is that whoever was caught in the flash would be walking around in a blinded stupor for moments after. This is because the flash bulbs of that time had a longer duration than modern electronic flashes. I'm not completely sure but I think this had something to do with wanting more of the ambient environment lit with the shallower depth of field of the large format cameras.

In any case, the central problem is syncing. When you fire your flash you want to be sure that the flash exposes what you want exposed when the shutter is fully open.

First, a little bit about shutter transport and sync speeds

What, you say? Isn't the shutter simply open and then closed?

No. A shutter is still a mechanism (not speaking of electronic gated sensors now). It can be a door that still takes time -- even if it is a fraction of a second -- to swing open and then shut. On a cloth shutter it is like the drawing of a blind where two curtains are quickly drawn over a window (a window to your negative). I mention this in part because my Pacemaker has a cloth shutter.

The length of the time it takes to cross the opening to the eye can be instantaneous but can still be measured. When you can measure shutter speeds to 1/5000th of a second in some cameras (up to 1/1000th on the Pacemaker) it really does matter if you can set your flash to fire at the very instant and duration that the shutter is open. This is called syncing. Every camera has a maximum speed at which it can signal your flash to fire: the sync-speed.

For my Canon 30D it is 1/250th of a second. For many older mechanical SLRs such as my Fujica ST705 and Pentax K1000 that number is 1/60th.

If the flash fires and the shutter speed is too high, it may catch the shutter before it has had time to completely transport. Hence some people's pictures with flash showing black bars or vignetting on one side of the picture. This page has a nice table showing the various results of too high shutter speeds.

The Pacemaker manual itself does a good job of describing the sync issue. Read p.15 of the manual.

The too high sync speed is a common and visible consequence with modern SLR photography and a similar problem exists with my Pacemaker.

Those old press photographers I mentioned had these bulky bulb flash systems and had to match the sync speeds of their press cameras for those bulb systems. They knew that the sync speed for the Pacemaker for their flash bulb systems was between 1/250th and 1/100th. But that does not matter to those of us with electronic flashes. It was synced to their bulb systems, not to our modern systems.

Bulb vs electronic flash

The key difference is that bulb systems needed time to build up their peak burn (where their light intensity is at its maximum) and thus were fired at the moment the shutter begins to open so that it would be at its peak when the shutter is fully open. In comparison, modern electronic flashes fire too quickly, not needing time to build up. So when a modern flash is ordered to fire by my Pacemaker, the shutter is only beginning to open and also since modern flashes have less duration than flash bulbs, their effect will be gone by the time the shutter is fully open.

This is something I discovered last night when I realized even after successfully connecting my Pocket Wizards to my Pacemaker with the aid of a Paramount bipost to miniphone connector that it just wouldn't work -- not without some workaround.

The solutions

So if the problem is that the modern electronic flashes are too quick for the focal plane shutter of the Pacemaker, what is the solution?

1. Get a lens with an X-sync (modern sync) P/C connector: yes, these are plentiful and if I had thought of it, I would have had one by now. Unfortunately, the Alphax lens that came with my Pacemaker does not have one and so I searched out a focal-plane solution. Also, this is no solution for those lovely primitive barrel lenses I described above since they have no shutters themselves.

2. Get a bulb flash. Yes, you can still get these on that awful auction site and from some reputable dealers. And yes, flash bulbs are still being made. At some point I may consider this but also I do have too much clutter already and have many, many other modern flashes I would love to use.

3. Forget flash. Use continuous light. Okay, my last lighting class was all continuous light but I'll let that go for now.

And the workaround

4. Flash with an open shutter - the workaround I am going to be trying immediately -- since the other solutions require getting more gear -- is to shoot with an open shutter.

Since the problem is making sure that the electronic flashes don't fire too early, the workaround is to NOT try and sync it.

Simply keep the shutter open for as short as one can manage manually, fire the flash manually while knowing the shutter is open, and then close or block the shutter manually using the (T) Time-mode (bulb mode in modern cameras).

The problem with this is that obviously with manual control it will not be at all instantaneous even with the aid of shutter releases. The negative will be exposed from the moment of time the shutter is open obviously until closed taking in any present ambient light. This will be a problem for metering unless you are in a very dim room or one must simply deal with unpredictable effects.

This will be my challenge for my first shot this weekend.

Links

Camerapedia.org - Graphlex Speed Graphic
How a focal plane shutter works
Graphlex Pacemaker Speed Graphic manual
Flash photography on Wikipedia
Flash bulb types
Parmount Cords: bipost. The bipost is the connector for flash sync cords.
Meggaflash.com -- makers of flash bulbs
Flashblubs.com -- excuse the cheesecake website
A discussion on Photo.net that provided background information for this article