Could use some help with a diagnosis

[bobwysiwyg]

I still very much consider myself new to LF, I'm trying to learn to use a 4x5 (Cambo). I recently shot a number of sheets while on vacation and just got around to starting the developing. It's TMax 100, D76 using a CombiPlan and Fidelity Elite holders.

Most of the sheets seem fine, but more than a few have a very broad, unexposed band which ends up making the processed format almost square (see attached image).
When I load film, the flap end is away from me with the film notches in the right-hand corner. I withdraw the dark slide enough to reveal the end of the film slot/track. Then I insert the sheet and make sure it is snug against the stops at the flap end before closing the flap and seating the dark slide.

It almost looks as though the sheet is riding up in the holder towards the open end. Could pulling the slide when shooting allow the sheet to ride up and thus a small strip never gets exposed? It seems unlikely. I've just tried a couple of the holders, one of which I'm sure was an offender, and there does not seem to be any way a sheet could ride up over the stops at the slide opening end. Any thoughts, suggestions would be appreciated. Thanks.

 

[winger]

When you shoot, are you pulling the darkslide completely out of the holder or do you sometimes not pull it all the way out?

 

[mpirie]

The blank sections look to me like the sheath hasn't been removed fully, thus leaving part of the film unexposed.

If the film had moved in the film holder before exposure, then the image would be all over the notch-end of the film?

Mike

 

[Thomas Wilson]

It almost looks as though the sheet is riding up in the holder towards the open end. Could pulling the slide when shooting allow the sheet to ride up and thus a small strip never gets exposed? It seems unlikely. I've just tried a couple of the holders, one of which I'm sure was an offender, and there does not seem to be any way a sheet could ride up over the stops at the slide opening end. Any thoughts, suggestions would be appreciated. Thanks.

The film "Riding up" would have been my first guess. But if you are satisfied that you can rule out that possibility, perhaps you are not fully removing the slide when shooting.

I have a few sheets of 4x5 film from my beginner days when I did just that. For some reason, that was completely logical at the time, I thought it clever to leave the dark slide just barely in the film holder. I was bracketing and not concerned with composition or focusing at that point; just the time needed to wrap up the shot.

Needless to say, I never repeated that mistake.

 

[DannL]

Two things come to mind. Firstly, I personally never withdraw the darkside completely from the filmholder, and occasionally have left the darkside in too far during an exposure. My darksides are now marked appropriately. But, I don't think that is your trouble here.

There is the possibility that the holder was not completly in the camera when you made the exposure.

 

[Rick Rosen]

Looks to me like the film was pushed down too far so that the end was riding under the flap.

 

[bobwysiwyg]

Thanks for all the suggestions. I have been withdrawing the dark slide completely since I started learning. Mostly because I'm fairly certain I would not do it correctly otherwise, ha, ha. I don't think I'm inadvertently sliding the sheet too far down towards the flap end when loading because I tried that a bit ago to make sure, with some scrap sheets I keep around. If you do, you can't close the flap, nor fully insert the slide and lock it without it being obvious. Now, on occasion, I have 'forgotten' to remove the dark slide, rather embarrassing. I re-cock the shutter and hope any uninitiated nearby think it was a deliberate practice shot.

Right now, I seem to be focused (no pun) on Dann's thought about not inserting the holder all the way. I thought I was, but perhaps not. I will load a couple of holders, even one that I know this happened in, and see what happens. Thanks all for making me think.

 

[ic-racer]

Push the film holder in farther. I think the film holder catching on the little lip and not going in all the way.

 

[ic-racer]

OT: How is the combiplan? A friend of mine just started 4x5 and wants to start a home darkroom. I suggested the combiplan but have never used it myself.

 

[calceman]

Do a "blank" test: use an empty holder and put it in position. Remove the lens board and remove the dark slide. Look through the front standard and you will see what's shading your negatives.

 

[paul_c5x4]

Re: combiplan - The supplied loading guides scratch the sheets as you load them. The securing clip is fragile and easy to break. Filling and draining chemicals isn't particularly quick, so it is much easier to fill with developer first then drop the film holder in.

I've switched to using a Paterson Orbital tray and keep the combiplan for second stage fixing and washing. It limits me to four sheets per run, but I can get away with 100ml of developer (usually use between 120-240ml). Using the combiplan tanks, 1l is required regardless of the number of sheets being processed.

 

[jbbooks]

It appears to me that you are not fully inserting the film holder into the camera.

There is a raised ridge on the film holder that will stop the film holder as you put it in the camera. Pull back slightly on the film holder and push it further in. When you do, the ridge will slip on past and allow you to fully insert the film holder and seat the ridge in the groove that is located in the camera back for that purpose.

 

[bobwysiwyg]

Good thought on the empty holder and checking through the lens.

As for the Combiplan, at first I was concerned about the amount of time to fill/empty. I was used to 35mm for so long where it all happens pretty fast. I just allow for the time to empty and found that filling goes faster if you don't let it 'pile-up' in the funnel, it works fine. No problems so far.

 

[bdial]

The slide shouldn't be able to contact the film if it's under the flanges, and your examples were. I've never had a reason to look, but I don't think there is any easy way for the film to travel out to the light trap.
I agree that the most likely cause is the holder isn't seated in the camera. It's easy to check, the holder should be all the way against the stop on the (usually) left side. It's a little surprising that you don't also have some fogging though. It would be a good idea to check the inside of the camera too.

 

[bobwysiwyg]

It's a little surprising that you don't also have some fogging though.

Not all, but one did. It leads me to believe even more, this is my problem. I'll check it for sure with some empty holders and be more vigilant while actually taking pics as well.

 

[bobwysiwyg]

Problem (this one anyway) solved. It was because I was not inserting the holder all the way as had been suggested. I finished processing the rest of the sheets and a majority displayed the problem in one form or another. In some instances, the unexposed band was, well, completely unexposed. In some instances there was fogging in the area and a few, even had fogging intruding in the image area. I'm guessing this difference was due to how far, or not, I was short on fully seating of the holder.

Now I feel confident that I won't repeat this problem and can move on to the next newbie mistake. Thanks all.