Graflok plate holder...?

[cpeterson]

Greetings everyone,

For a few weeks now I've been trawling around for information about holders for glass plates. While I've found lots of info about shooting film in a plate holder, I've found little about going the other way around -- I want to shoot plates with a more modern camera, a crown graphic (or any of the monorail cameras at school). Disappointingly, I've found not one word, not a single whiff about the existence of a graflok plate holder, so I presume I will have to either fabricate one or modify an existing holder.

Okay, okay, I know this might be a fool's errand, but bear with me here.

I've already determined that conventional film holders aren't suitable for modification, due to the width of the rails and the odd physical dimensions of cut 4x5" film. But what about those old graflex pack film holders?

The pack film holders have a generous amount of space inside and look like good candidates for modification. I'm thinking that my design would involve welding or riveting some springs onto the inside back so that the glass plate is held tautly forward, and then adding a similar mechanism with a spring on one end and a stop on the other to hold the plate centered horizontally.

There are some other design details (like getting the latch area light-proof) but what I'm primarily concerned about is the feasibility of such a spring setup. Am I correct in assuming that a plate held forward against the bezel of a pack holder would be in the same plane of focus as my ground glass?

I would love any comments or even any speculation on other design possibilities. I won't be told no!

[Ole Tjugen]

An interesting question, and one to which I have no answer - only more confusion.

In the "transition time" between plates and film, there were several different kinds of adapters going both ways. The film sheath inserts for plate holders are familiar, less so are the "Universal Cut Film and Plate" holders. I've got a few of those in 9x12cm, 4x5" and 13x18cm (Linhof, "mit Auswerfer"), and they really do work. Except some "modern" 9x12cm plates which are thicker than the real stuff...

There were also some slip-in adapters made, to use 9x12cm single-plate metal holders in modern "international" backs. And for 10x15cm or 13x18cm plates in 13x18cm (5x7") cameras. I've got a few of those, too...

So the possibilities are there. Or at least they were there, back in the days when people used both and wanted their new modern camera to use the same plates they'd always used!

[Paul Ewins]

The pack film adapter should work, although you will have a fair bit of work to keep it all light tight. You'll probably need one that has the pack still inside it to get the film plane at the correct distance. From memory the film pack as springs in it to push the film forward so you might be able to reuse those.

Here's a page describing how I converted a film pack into a focussing panel:
http://members.optusnet.com.au/~paul..._graphic_2.htm

There was one version of the Graflex bag-mag that was specifically for glass plates. The trouble here is that the registration distance for the Graflex back is larger than on a Graflok back so you would have to sand back the face by a couple of millimetres. The sides are wider too, but they could be narrowed wiothout too much trouble.

http://members.optusnet.com.au/~paul...ces/bagmag.htm

[jnantz]

you might contact places like equinoxphotographic and pacific rim camera they tend to have film holders at least for not too much $$. they won't have multiple plate holders ... if you don't mind changing cameras/formats you can always look for a falling plate camera . they took plates and as the name suggests, the plates were upright in the back of the camera, until exposed then it fell to the bottom of the camera ... they made cyclone sr cameras that were 4x5. there were other format sizes as well ( long and skinny ).

good luck!

-- john

[Bart Nadeau]

I think it would be so close it wouldn't matter. The metal holder that the film that is in the film pack is in is very, very thin - perhaps .0005. That would be such a small difference that it shouldn't make any difference in anything except major macro photography.
That said, Graflex Inc. made modern double sided plate holders up at least into the late 1950's. Look just like late model, type 5 black painted wood, film holders. Catalog number was 1224. Cost $7.45 ea. as oppposed the the Graflex, Graphic/Riteway film holder #1284 @$4.95.
I've seen these come up from time to time, sometimes in near new condition.
Bart

[Paul Fitzgerald]

cpeterson,

Fairchild also made the Graflex 'bag-mags' for aero cameras. My 5x7 has plate holder septums backfilled with masonite to use film and to make them very stiff. I think they also made them in 4x5. Worth a search on Google.

It would be easy enough to make a GG holder insert to match the 'bag-mag' instead of modifying your Graflok GG.

You might find a sheet metal fabricator to make-up septums for the glass plates to fit a regular 'bag-mag' but you would also have to open up the bag side slots to match.

Have fun with the hunt.

[cpeterson]

Well, things have gotten a little more interesting!

First off, thanks John for the link to Equinox, I did e-mail them and they said they have a couple of holders that will fit my camera. That's curious -- how can they be so sure? Still, the price isn't terrible, so I might order them, just to see. I doubt they're graflok-style but they might easily be adapted to fit under my spring back.

I’m worried about focal plane registration, though, both for Equinox’ mystery holders, and for my theoretical film pack adapter modification. I did try a little experiment but I’m somewhat confused by my result.

I took a sheet of ground glass and duct-taped it into my adaptor back, ground side toward the lens, as I would do with a plate. I then took my camera outside and focused it on a distant clump of trees. Noting the position of the focusing rails I then removed my simulation plate holder, replaced the spring back, and refocused. There wasn’t much difference, maybe a millimeter.

I repeated this experiment at 5 meters, 1 meter, and one foot and the focus delta did not seem to change. In fact, for the two closest tests, the focusing didn’t seem to be off at all, or at least, the change was so small that it was less than the play in the teeth of the focusing rails.

I have to say, this is not what I expected; I anticipated the focusing delta would grow geometrically with focus distance. Perhaps I should re-do my test to verify this.

The bag mag is an interesting contraption, at least one worth looking into. I’ve never heard of it, I suppose I’ll educate myself this morning over my second cup of coffee.

Thanks everyone so far.

[cpeterson]

Well! It's been a couple months since I posted this thread, and my emulsion-making / plate-coating project has come a long way. In fact, I'm not far away from having results -- in 24 hours, I'll be developing my first samples.

I wanted to say here though that, in spite of speculation to the contrary, my pack-film adaptor conversion has worked, at least to an acceptable degree. In fact, once I finally got around to working on it, it was barely an afternoon's work.

In the body of the pack holder I've placed a cutout mask of foam-core that the plate slips into. One edge of the cutout is missing and in its place is a piece of weather striping, exactly like what you'd put on a door to keep out a draft. There is a piece of matboard that lays on the back of the glass to serve as a pressure plate and to absorb reflections.

Some more weather striping and gaffer's tape renders the unit practically light-tight, tested by holding it at all angles to a 1k studio hot light. (Edit: with live film in the holder, naturally)

What's more, the plate is held in proper registration with the camera's ground glass. I did some preliminary testing a few weeks ago but performed the real thing a couple nights ago; I taped a sheet of FP4+ onto the front of my dummy plate and developed a focus check. Everything was in order.

I'm attaching a couple pictures of the converted plate holder to illustrate the above description. I shot the pictures before I finished the project, so try to imagine some more weather striping filling out the area near the clasp, and some gaffer's tape on the top and bottom ridges.

[j.e.simmons]

Just ran across this thread. I have some Graflex plate holders that were made to fit in a Graflex back - the slotted holders for the back generally found on the SLRs. These holders will fit in a Graflock back, too. In fact, I use my 2x3 Graflex holders in my Mamiya RB67.

I'm glad to see your conversion - it's good to see that someone has finally found a use for the flim pack adapters.
juan