How to test Graflex FP shutter?

[Dan Fromm]

But this is a 3-1/4x4-1/4 (don't tell the moderators) so no roll back is available.

But Mark, there's a 3x4 AAR 620. Uncommon, but they exist. I had one years ago.

[BrianShaw]

Dan, I like your thinking. Thanks for thee Calumet recommendation. But this is a 3-1/4x4-1/4 (don't tell the moderators) so no roll back is available- and I won't even have film until October if Ilford is on schedule. I'm restoring the camera after its decades-long sleep in someone's damp basement, and want to have as much right as I can before I start exposing HP5 at $3/sheet. I admit that this is not, perhaps, the smartest way to do things, but I'm going to try anyway.

Naughty boy, Mark.

[Jac@stafford.net]

Dan's method is my favorite, and you can do 'test strip' shots with sheet film, although you will have to use a few sheets.

I recently gave up trying to tune a Graflex FP shutter. At one point I tried to measure speeds relative to each other (as in stop-to-stop) by illuminating from the ground glass plane and measuring duration from in front of the lens. Quite clever, I thought, but consistent curtain travel speed was the devil. Maybe I'm just not smart enough to fix it.

[BrianShaw]

That is why I "spot checked" mine. Took a few pics on E-6 at the various tension settings and compared. My assumption: if E-6 exposed good enough then the shutter speeds were good enough. And also assuming that the greatest source of variability will be the shutter curtain spring.

[Mark Sampson]

Dan, thanks again for the word about the Adapt-a-roll. My first LF camera, back in about 1977, was a similar 3x4 Graphic. I looked for a rollfilm back for it then, without success- of course knowledge, and obscure/obsolete photo hardware, were harder to find pre-internet. But I intend to use sheet film with this camera, unless one of those unicorns falls into my lap.

[AtlantaTerry]

Audacity will not work with the focal plane shutter in a Graphic or Graflex.

Why? You made a statement without backing it up. So why won't Audacity work as described by Bill_4606?

[unixrevolution]

Try searching the forum for Audacity. It's a free software download that can hear your shutter through your computer's microphone and record the sound on the screen. You'll read a lot of pro and con comments about using the tool. The one thing that nobody could argue away though is the cost... Time and effort to use it is minimal depending on how you are with following the installation instructions.

One advantage I found with the sound method is that it helped detect a bit of a shudder as the curtain slit swept across the sheet film... a kind of "shutter shudder" if you will. It caused a bit of a banding effect on the negative. There was a clear sound record on the screen that corresponded with the anomolly on the negative.

There are other free or very cheap apps and programs that do a similar job...

Bill

Audacity is my go-to free recording software. Free as in speech, as well as free as in beer

Why? You made a statement without backing it up. So why won't Audacity work as described by Bill_4606?

Because of how Focal Plane shutters work, and the fact that Audacity is a sound recording tool. The sound they make is during their whole travel, but the actual exposure time is determined not just by the spring tension that controls the actual speed of the curtain, but the slit width. It would be at best difficult, and at most impossible, to correlate the time it takes the curtain to start and complete its movement to actual exposure times. That, and the sound occurs before a visible slit shows, and stops after it disappears, so correlating the sound to an actual shutter speed is very difficult by this method.

The DSLR method mentioned above is how I would do it, if I could be bothered. My Graflex is "Close Enough" and produces good images at all shutter speeds. that's all I need from it.

[Jac@stafford.net]

Why? You made a statement without backing it up. So why won't Audacity work as described by Bill_4606?

To supplement Erik's good explanation, shown below is a drawing of the Graflex focal plane shutter. Hope it helps.

[Michael Cienfuegos]

If you have some 3x4 sheet film holders you can cut some x-ray film and use it. The stuff is much cheaper than that wonderful Ilford stuff. I'm down to my last box of Efke which I had in the freezer. I have one box of Ilford FP4+ and then it will have to be xray film.. I also have a few Graflex SLR's, but they use a different back. I have roll film holders for them, but prefer to use the sheet film.

[Jim Jones]

Why? You made a statement without backing it up. So why won't Audacity work as described by Bill_4606?

Photography is recording images with light. Audacity merely notes the noise a shutter makes. This can have little relation to the amount of light the shutter (and diaphragm) pass. Relying on Audacity to accurately measure effective shutter speeds is rather like measuring someone's IQ by the size of their boobs: sometimes it seems to work.