Accidental light exposure with Grafmatic film holders

I'm wondering anyone has any experience with how good Grafmatic film folders are at shielding all the other sheets from fogging, if you accidentally totally nuke the top sheet with exposure. I expect that I'm going open the dark slide while the lens is open every now and then. I already did this with a holder filled with E6 film, and I haven't gotten it processed yet. I'm guessing if the dark slide is closed with the top sheet exposed, the other sheets should be fine if I blast the top sheet with light. I just over exposed an IR sheet by 6 stops by forgetting the filter when switching back and forth from IR and non-IR film.

The situations I tend to shoot in make me prone to mistakes. Often, I exhaust myself hiking out to hard to reach areas with a heavy backpacking backpack filled with gear. I'll then wait for lighting conditions that'll last for 10 or so minutes, and then I'll run from location to locations trying to get all the shots in while I still can. It can be easy to blow it in these situations.

Grafmatics are very good at protecting the other sheets unless the dark slide is left hanging out. The you would get bleed through on the thummb holes of the septums.

Checklist/process and stick to it. Really. Large format is a fairly involved business when one awake and fresh You have to tailor your expectations.

As the saying goes 'Slow is Smooth. Smooth is fast.'

The one big disadvantage of Grafmatics is that once you pull the darkslide out you're committed to taking the shot. The top sheet will be unprotected after reinserting the darkslide. It only becomes protected when you advance to the next sheet.

Your example is the worst case scenario for Grafmatics, since you might be waiting for light to change before taking a shot, but if the light doesn't change you're stuck having to advance to the next sheet, if you don't want to take the shot. You can get around this be keeping track of what sheets haven't been used, and cycling back to them later. This can get really complicated, and could result in even more screwups.

I'd suggest using conventional film holders instead. With conventional film holders, the film is always protected when the darkslide is inserted. There's fewer things to go wrong, but at the expense of more weight and bulk. As with everything, there's no free lunch.

I guess the holder full of E100 is a total loss. Quite an expensive mistake.

I've taken to bringing along sharpie to take notes on the back. Sometimes I might want to push a couple sheets.

Also, I've just found that Rollei IR can have problems with these film holders. The base is super thin and can fall right out of the septums. I had this happen the other day, when pulling out the film drawer in a vertical position. A sheet fell out and got totally crumpled up when I tried to push the drawer back in. I had to cut the shoot short, go home, and deal with it.

Now I plan to only do this when it's in a horizontal position.

I recently got an Grafmatic 23 for my Silvestri 6x9.
In the beginning of the inevitable learning curve, I encountered unexplainable fogging of a part of the sheets positioned below the one which was 'in use'.
Then I saw that the the frame holding the whole pack of the 6 septums moved along with the dark slide.
What happens to my few insights of a beginner, is that when pulling the dark slide, then the whole pack is partially coming out of the holder and fogging all the sheets.
What happens is somewhat the same as you would load/unload the septums: perhaps page 3 of the user manual I include as an appendix might explain what I am trying to say...

Look at the top illustration, there you see fingers holding the cassette where in the septums are lodged. When you pull the dark slide too hard or 'unevenly' and hold that chrome latch a little too long, the cassette has tendency to 'follow' the dark slide.

That is how I see it, but my English is clearly not 'developed' enough to explain it more comprehensively, sorry for that...

Sharktooth said:

With conventional film holders, the film is always protected when the darkslide is inserted.

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Grafmatics were designed for rapid shooting -- a press photographer (especially one doing sports or similar action photos) could shoot six frames in four or five seconds (with a press shutter in the lens) -- and swapping to a second Grafmatic barely takes longer than changing film holders with conventional double dark slides.

If the dark slide is closed, only the top sheet is unprotected, based on handling my own Grafmatics, the sheets behind are protected by the darkslide. You should always close the dark slide in order to be sure the septum on top is correctly positioned for accurate focus, so the only chance of exposing other sheets than the top one is during the actual cycle; I'd have to look at my Grafmatics to check, but I'm fairly sure the sheets behind are protected even during the cycle, either by the dark slide and drawer, or by the topmost septum.

Even the worst case is not destructive to all area of all sheets but it will destroy top sheet and edges of two or three sheets under.

Example: Your springs are loose and as you pull the body from the shell you lift the entire Grafmatic away from the camera.

I had that happen once and only lost what I described: top sheet and edge fog on couple sheets beneath.

Donald Qualls said:

Grafmatics were designed for rapid shooting -- a press photographer (especially one doing sports or similar action photos) could shoot six frames in four or five seconds (with a press shutter in the lens) -- and swapping to a second Grafmatic barely takes longer than changing film holders with conventional double dark slides.

If the dark slide is closed, only the top sheet is unprotected, based on handling my own Grafmatics, the sheets behind are protected by the darkslide. You should always close the dark slide in order to be sure the septum on top is correctly positioned for accurate focus, so the only chance of exposing other sheets than the top one is during the actual cycle; I'd have to look at my Grafmatics to check, but I'm fairly sure the sheets behind are protected even during the cycle, either by the dark slide and drawer, or by the topmost septum.

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That's completely correct.

The septum container is spring loaded, so when you pull out the darkslide the septums want to pop out. That's why you need to push the septums down after loading them, in order to push in the dark slide.

When the septum container is pushed into the main body of the holder, all the septums are protected. The holder can be put in the camera like any other holder, but when you pull the darkslide, the topmost septum is "popped" up out of the septum container by spring force. The gap above the septum container is only big enough for one septum. When you push the darkslide back in, it goes under/behind the top septum. This means the top septum is completely unprotected now, and ready to be exposed in the camera. The remaining 5 septums are behind the darkslide, and are completely protected. The difference here is that you have to take the shot and cycle the top sheet back into the protected container. If you don't cycle the system, then the top sheet will be exposed when you remove the holder from the camera.

You also can't cycle the system when it's outside the camera, since the camera blocks light coming in through the open area when the septum container is pulled out.

I looked at my 2x3 Grafmatics over the weekend, and I do see one weakness. If you cycle the Grafmatic off the camera, there will be a moment when the (new) top septum is exposed to light, but the dark slide isn't in place behind it, and light that manages to get through the film will pass through the finger notch at the open end of the septum and fog a small area of the next sheet. Depending how bright the ambient light is, you might even see fogging on third or fourth sheets.

This would be a pretty heinous handling error, though. Certainly not something that will likely happen to an experienced user.

But a loose Graflok bar has bit me once or twice.

Bill Burk said:

But a loose Graflok bar has bit me once or twice.

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Sure, but that isn't a Grafmatic problem as such -- that'll give you trouble with a roll film back or LomoGraflok, too. This is especially something to watch for with the 3D printed Graflok conversions for older Speed and Crown Graphics, BTW. I had to do a little troubleshooting on mine from 20th Century Camera to get the bars to hold tight.