Diagnosing Banding — Not shutter, not developing streaks...

[Takkun]

Excuse the terrible photo, but it shows what's going on.

Souped my first roll of Silvermax (Xtol 1+1 for 9m, a bit thin but useable) out of a Bessa R3a, and some, but not all, frames have this strange banding. Sometimes, like this one, it's a lighter strip with a darker band to the left, in others, it's just a darker band. Nothing like this on the last roll I shot through this camera, which was TMY.

What it's not:

Scanner: It's visible in the negs.
Shutter: Vertical-travel shutter, this is always a vertical bar.
Development: No streaking across the frame, always in the same spot on the left. Not like what I've seen with stand dev gone wrong.
Light Leak: Uniform density change, nothing between frames. The bars are usually darker, not lighter. Where they are lighter, like in this example, it does go into the rebate/sprocket hole area.
Bulk Loader Leak: Again, uniform location in the frame.

Any ideas? I'm guessing it didn't get fed into the reel correctly, but I'd assume these bands would appear somewhat randomly.

 

[retinax]

Are you absolutely certain that the band is sometimes darker in the positive? That's very odd. If it weren't for that, I'd say light leak from the hinge.

 

[Bill Clark]

Vertical shutter.
Vertical light on neg.
Same spot.

Shutter issue? Maybe something around the edges (gasket) causing it?

What make of camera?

Nikon?

My Nikkormat has vertical travel shutter.

 

[Carlos Cruz]

Is there any chance you're bulk loading and your stock went through X-rays? Try developing some unexposed stock.

https://www.kodak.com/global/en/service/tib/tib5201.shtml

 

[Larry H-L]

The way it fades off makes it seem like a light leak to me. But wouldn't the leak would be on the closure side, not the hinge side (remember, the picture in-camera is upside down), Bessas have the hinge on the left???

If the camera sits for a long time, is it more likely that the first new frame has the banding? If frames taken in quick succession don't show it, that is another indication of a light leak.

 

[Peter Jennings]

Perhaps some kind of flare from a surface in the camera? It's hitting the film at an angle, so the dark band is caused by the film gate blocking the flare.

 

[Malcolm M]

If it's always in the same place on the negs, it must be happening in camera. It it's affecting the areas outside the image, then it's presumably not during exposure. Could it be fogged leaving the cassette? The dark band is unfogged film in the cassette, and the light band fogged immediately outside the felt?

 

[retinax]

The way it fades off makes it seem like a light leak to me. But wouldn't the leak would be on the closure side, not the hinge side (remember, the picture in-camera is upside down), Bessas have the hinge on the left???

If the camera sits for a long time, is it more likely that the first new frame has the banding? If frames taken in quick succession don't show it, that is another indication of a light leak.

The hinge is on the right from the camera user's perspective. In any case in can't be from the other side as the cassette is there. The light would be falling on the frame that was last exposed and moved to the take-up spool already.

 

[Arbitrarium]

If it's affecting the areas outside the image, then it's presumably not during exposure. Could it be fogged leaving the cassette? The dark band is unfogged film in the cassette, and the light band fogged immediately outside the felt?

This is my assumption too. A leak happening in the gap between the film canister and the pressure plate.

 

[Takkun]

Here's a better look at the negatives, the above frame and its neighbor.

As I mentioned, this is a Bessa, hinged back. Film being exposed upside down, this means whatever it is, is on the right side of the camera, so likely not a leak on the canister/film reminder window side.

But note the strip of less density in the preceding frame. Less, not more, like something's blocking the light.

As I'm often prone to do, a few blank shots and overexposed shots (coming outside and forgetting to change exposure, vice versa) and neither effect shows up in those.

A few minutes ago I wasted a few frames and cycled the shutter on B-nothing obstructing, shutter looks to be operating properly.

It's baffling.

 

[retinax]

Whoa this is baffling. How can one get less exposure in part of the image if it's not the shutter? Seems impossible, there would need to be something like an piece of ND-filter in front of the film, there is a good amount of exposure after all... is this the extremely unlikely event of two faults at the same time?

 

[Takkun]

Whoa this is baffling. How can one get less exposure in part of the image if it's not the shutter? Seems impossible, there would need to be something like an piece of ND-filter in front of the film, there is a good amount of exposure after all... is this the extremely unlikely event of two faults at the same time?

I know, right? I should have posted both images rather than just the one that looks suspiciously like a light leak. Most of them have the strip of low density (example on the left) and only a handful have an additional strip of higher density that extends past the frame. Images are sharp, so nothing warping it in the film path or anything.

One thought was that there was a small sliver of film, left over from trimming, somewhere in the light path. Couldn't find anything.

On the plus side, I think these negs were a little underexposed and needed another minute in the soup, but I'm blown away by the tonal range regardless!

 

[Steve M.]

Probably a light leak. Tape up the camera's back with electrical tape along every seam and try another roll. Or, take the camera into a closet, remove the lens, and shine a bright light into the front and see if there is light leaking around the back door. If it were me I would just replace the camera's seals in the back and be done with it.

 

[Larry H-L]

I don't think frame # 2A has less density at left.

To me, it looks as if the left side of that frame is normally exposed, and the entire 7/8ths right side of that frame has additional exposure from light leak fogging.

Look closely at the sprocket area... it is fogged compared to 1A-2.

 

[Takkun]

I don't think frame # 2A has less density at left.

To me, it looks as if the left side of that frame is normally exposed, and the entire 7/8ths right side of that frame has additional exposure from light leak fogging.

Look closely at the sprocket area... it is fogged compared to 1A-2.

I think you're right. It's very, very hard to tell, but that looks to be the case, and the bands that are strongest are on frames where I went a little while without taking pictures. I shot the whole roll in about two hours between two locations (interior/exterior), and they show up strongest on the first shot of the new area.

So that changes my hypothesis a bit. Lining up the preceding frame to the film gate, the 'dark' band on the next frame corresponds exactly to the bit between the edge of the gate and the cassette chamber. Meaning that, with the rest of the frame other than the band fogged, light is getting into the bit between the cassette lip and the rails. Hence the bright spot when the film is sitting fo a while, and fogging as the film is advanced.

The seal (with this camera there's only one bit of foam around the indicator window, the rest are light traps) looks fine, no squishing or distorting. I wonder if the cassette itself wasn't seated fully.

 

[JoeV]

A bit of light falloff near the edges will make the band at the very left side appear brighter than the center of the image.

I agree with the light leak theory, should be straight forward to diagnose with some black tape on the outside of the camera at strategic places, as you expose a test roll.

 

[ColSebastianMoran]

Light leak torture test:
- Three blank frames in quick succession
- Leave camera in bright light for a couple of hours
- Then four more blanks in quick succession
- Shoot the rest of the roll if you wish

My theory is light leak. When it happened to me, it was the film door hinge, so the leak was not on the frame behind the shutter.

 

[sepiareverb]

I might suspect the cassette. Does this happen at the start of the roll only? Seems like it could be some bad felt on the cassette letting light leak in before it goes in the camera. You mention TMax was unaffected, so that would point to the Silvermax film or cassette being the culprit?

Was the TMax bulk loaded as well?

 

[Malcolm M]

Having seen the photo of two consecutive negatives, I stand even more strongly by my original diagnosis. The fogging is in exactly the same place (just clipping the 1st sprocket hole) on both. The film is being fogged between cassette and pressure plate, and then moved into the image area when wound on.

 

[Takkun]

i did suspect the cassette at first, but it's looking more and more likely a leak. Developed the second roll shot the other day, as well as a roll of TMY with ColSebastianMoran's test completed...it's there again, both the 'dark' and light streaks.

The other head scratcher is that the only foam seal, the annular one around the film indicator window, looks fine—supple with no compression. That's the most likely point of entry.

So I'll put forth another hypothesis. Lately I've been using a P-Touch labeler to mark my cassettes instead of a strip of masking tape with hastily scribbled notes. I've been putting these where the film reminder window would let me see them, like on a factory-rolled cassette.

The labeler strips are laminated, gloss white. Could it be that, somehow light is being piped through the label material and under the seal?