Graflex.org

[frohnec]

I just purchased this camera. I know just about nothing on operation.
What does the plate on top of the camera with the tension numbers mean?
Chris

[t.r.sanford]

The plate atop my "Anniversary Speed" lists four "curtain apertures," identified as A through D, and six "tension numbers," 1 through 6. I suppose you are looking at pretty much the same plate (although, on some models, the curtain apertures were identified by widths in inches).

This all is used to set the focal plane shutter for a particular speed, and the plate tells you what those speeds are. To set the shutter, you use the key and the knurled knob on the right side of the body.

The key winds the focal plane shutter curtain around a roller running across the inside of the camera body.

The knob varies the tension of a spring inside a companion roller running across the inside of the bottom. That spring rotates the lower roller, pulling the curtain down, unwinding from the top roller and winding onto the bottom one.

Winding the key brings a series of letters (let us say) into view in the little round window below the key and above the dogleg shutter release lever.

O means the shutter curtain is Open; you want this position if you are using a lens built into a "front" shutter.

Wind to the next detent, and you get T. T means the curtain is now closed and ready to make a Time exposure when you press the release.

Wind again, and you come to A. A is the widest curtain aperture. You can see where this is going... D is the narrowest.

You use the release lever to back the curtain down, from D through C and B to A, T, O, and the final, rest position, in which the curtain is wound fully around the lower roller, under no tenstion. (That is where it ends up when you press the release a second time to end your Time exposure.)

If you want to make Time exposures, with the T visible in the window, press the release lever once; you hear a zip, and the O appears. Press the lever again to end the exposure, and you hear another zip, and the O disappears.

(Many Graflex shutters need a little help closing after a time exposure, unless adjusted and lubricated. You will find much discussion of that topic on this site. You can improve matters by using the tension knob.)

Winding up tht knob, you start with 1 (the least tension) and work your way up to 6 (the greatest tension). The little pawl to the front of and below the knob is used to back the tension down, from 6 to 1.

The plate on the top tells you what shutter speeds result from each combination of a letter (or width) and number. For example, the narrowest slit, D (sometimes called 1/ and the highest tension, 6, gives you 1/1000 of a second. That was a wonder, in the first decade of the 20th Century, and it is why the camera is called a "SPEED Graphic."

Similarly, aperture B (sometimes called 3/4) and tension 5 gives you 1/125 of a second. And, of course, if you happen to need a 1/320 sec. exposure, you can select one by matching aperture C with tension 4. (Few cameras give you this option!)

When making a Time exposure, it's helpful to set the knob to 6 (highest tension), which makes the curtain open and close briskly. When finished, it's a good idea to back it down to 1, to take the tension off the spring.

If you don't plan to use the FP shutter, make sure the tension is wound all the way down to 1 (to preserve the spring in case you ever do want to use it), and the O is visible through the round window. You may then forget about it, as many people did, when these cameras were in common use.

If you do plan to use it, you should remember that it differs from the kind of focal plane shutters found in miniature cameras. It has only one curtain, not two, and so is not "self-capping." When you wind up the key, the slits move slowly up past the film gate, one by one. If there is any film there, it's going to get fogged.

This calls for a disciplined approach to the use of film holders. Always wind up the curtain (or back it down for a slower shutter speed) with the darkslide in place, or the film holder out of the camera back altogether. Run through the entire sequence of setting the shutter, setting the lens diaphragm, pulling the slide, making the exposure and replacing the slide, a few times and it becomes reflexive.

This is a very versatile, well-engineered shutter, which is why it lasted three-quarters of a century with little change. It simply requires a bit of thought and practice to grasp its logic and make the procedure automatic.

[frohnec]

I think i understand.
There are two shutters.
One on the lense.
Second is the wound focal plane shutter in the back of the camera and looks like a curtain.
As you turn the key - as you suggested - through the letters you can see the different openings in the "curtain" focal plane shutter.
So if I want to use the shutter on the lense where the speed can be set then I would put the curtain - using the key and wind to the "O".
Yes?
If I wanted to use the curtain - focal plane shutter - then I would put the lense shutter on T and then figure the shutter speed and etc by using the curtain a - d and the numbers on the knurled handle 1 thru 6.
Yes?

[t.r.sanford]

Yes. When the "Speed Graphic" first was made, front shutters were pretty primitive and either limited or unreliable. The focal plane shutter -- the Graflex shutter was a single long fabric curtain with slits cut in it -- gave you the ability to use any lens, including the great majority that were not mounted in shutters.

As interlens (leaf) shutters improved, more and more lenses came mounted in them; but as recently as 1960, the majority of large-format camera lenses were offered in a straight unshuttered "barrel" version and a couple of interlens-shutter options, a simpler and a more sophisticated. The prices increased accordingly.

Today, you can find a vast range of wonderful "barrel" lenses, almost always at much lower prices than the same lens in a working shutter. So your Graflex FP shutter gives you access to a wide assortment of high-quality optics at the best prices.

Its limitation, of course, is that it is very limited in its ability to work with flash, and in fact it will not work with electronic flash at all. For that, you need a front shutter.

As you deduced, the simple trick is to make sure the FP curtain is open (O in the little round window) when you're working with a front shutter, and conversely, to make sure the front shutter is open (by using the "Time" setting, or by means of a "press focus" lever or button offered on many shutters) when you're working with the FP shutter.

[45PSS]

Or as many of us do, Just pop open the focusing hood with the lens shutter open in either focus or T and verify that light is reaching the ground glass.

_________________
The best camera ever made is the one that YOU enjoy using and produces the image quality that satifies YOU.

[Les]

Since I use the front shutter exclusively, I always remember

"O" is for Open
"T" is for Trouble (cause the FP shutter is closed when set to T)

[t.r.sanford]

Too true! Those of us who shared one camera among several people always looked for that "O" when it was our turn, because the previous user may have had a perverse sense of humor...