Vertical Banding on my Negatives

[Alex Milne]

Dear all,

I've seen this problem off and on since I started using my Toyo 45A a few months ago. My first forray into LF. Basically it is vertical banding. The example I have put on the web is the most extreme example but illustrates the problem. Most times it is very much more subbtle. I have bounced the possible reasons around and changed the way I do things to try and get rid of it without success. Specifically could it be a dark room problem - I develop my 5*4 negs in trays. Finally decided not. Could it be a dark slide insertion problem related to badly inserted film in the holder - could be? A lot of the problem negs have obvious evidence of slight rotation and I have occassionally problems putting the dark slide back in. Finally could it be a light leak while loading film in the field using a chaging bag?

Ho Hum

Alex.

http://www.mountain-photography.net/new_page_89.htm

[Martin Patek-Strutsky]

Had a similar problem. Found out that some of my older film holders are not light tight when the darkslide is pulled completely.

The problem disappeared when I pulled the darkslide only immediately before exposure

[Martin Patek-Strutsky]

sorry, was a little too fast. Have looked only at the banding on the right.

Could it be a processing problem? Do you have the same problem with slides?

[John Hoenstine]

When shooting veritcles do the bands run the long dimension of the film or are they still on the short dimension? Also when you tray process do you process emulsion up or down?

[Bruce Watson]

It's not a light leak. At least, it doesn't look like any of my light leaks. When a holder leaks, it almost invariably leaks from the light trap (where you insert the dark slide). This fogs the film from the light trap side in toward the middle. You'll see it fog the non-image area the most, and the fog will fan into the image area. It won't band like this.

If I had to guess, I would say that you aren't pushing the film into the developer all the way. You may be dropping the film face up into the developer tray. One end will go under, hit the bottom, and stop while the other is still above. You drop the next sheet on top of the first, and more the first sheet goes under.

All the books say to drop the film in face down, then push it completely under using one of your pinkies (so you don't get developer on the fingers used to pickup and position the film). If you aren't using this technique, consider adopting it. Or, go to rotary processing.

[Ole Tjugen]

It looks a bit like one of my light leaks - except that mine are parallel to the long side of the negative.

[Andrew O'Neill]

I too am thinking along the lines of what John asked. The bands appear same width and spacing. Almost looks like the grooves at the bottom of tray. I had similar problem but bands ran the long width of film. Have you tried changing the orientation of your film in the trays? Turn them 90 degrees (clockwise or counter) when agitating. See if this helps.

[Alex Milne]

Thanks to all for the rapid and erudite responses.

In answer to the questions:

(1) Do I have the same problem with slides. So far I have only done B&W negatives.

(2) I don't shoot verticals only landscape (sorry if I sound veruy dull!!!)

(3) When I tray process and shuffle the pack as recommended. I also push the negs in and make sure they are submerged. ie. face up then face down then face up etc.

(4) Looking at the trays the ridges run parallel to the long axis not oblique so I am struggling with this being the source of the problem.

The more I think about it and look at my camera I wonder if this may be related to sticky dark slides. Let me ask this - were there to be resistance while pushing the dark slide in could the opposite side of the back open ever so slightly and allow light in. Now if this happened twice with say two attempts to put the dark slide in then perhaps just perhaps we would see banding and increased light from right to left? Is this too whacky or possible?? I never have the dark cloth over the camera at this point. Remember I am a self taught novice who tend to get blown about a bit is the high mountain winds.

[John Hoenstine]

I've had my 45A for about 20 years and unless they have changed the backs a lot I would break the dark slide before I can get the holder to lift. Try shooting two exposures of each shot. Process one yourself and have a friend or lab process the other. You might even want your friend to load the one holder in his darkroom and you load your own in your darkroom. This will tell you if it is in the camera or the lab. I'm not sure but it looks like a darkroom problem and it could be happening either before or after the exposure. Good luck.

[wfwhitaker]

I'm still thinking it may be a processing issue. Do you use a pre-soak bath before the developer tray? Do you use a staining developer such as Pyro? I had a lot of trouble with uneven development initially with PMK. When I started using an alkaline pre-soak (PMK "B" solution only at standard dilution) the problems all but disappeared. But the idea of a pre-soak is a good one for most developers, even if it's only water to help "condition" the emulsion to receive the developer evenly.

What size trays are you using? 4x5 trays for 4x5 film is too small. How many sheets do you develop at once? Have you tried only one or two sheets to see if the problem remains?

And while tray developing is traditional (and sometimes the only option for large negatives), a rotary processor such as the JOBO Expert drum works great for negatives up to 8x10. You don't need the whole processor, just the drum (which is expensive enough). The JOBO roller base is inexpensive and allows you to roll the drum by hand. I think it beats the heck out of trays.

My $.03; Good luck!