What caused these dark bands?

[leonard_evens]

The attached images were made on Ilfor HP5+ 4 x 5 sheet film and

developed in D76 1:1. Both images were shot at f/22 at 1/125 using a

90 mm lens. I've been using this combination in a Beseler drum for

over a year and a half. The only problem I've had up to now has been

occasional shifting of film so one sheet overlaps another and leading

to undeveloped film, and that rarely. The dark bands in the images

were of course light bands in the negatives. The developer was over

6 months old, and I presume that was the source of the problem, but

two other sheets in the same run are okay. The sheets with the bands

were exposed the same day; the other sheets a week or two before.

 

Can anyone think of anything else which might have caused such a

problem except for uneven development? It is remotely possible

something was hanging in front of the lens of something similar but I

doubt that I would have missed that. Any obscure optical principle I

don't know about? As you can see from the shadows, one of the scenes

was back lit and I must have used the dark slide as a shade to keep

light directly off the lens. But the other was side lit and I don't

think I bothered.

[benjamin_lineberry]

Hmm. Looks like "bromide drag". Uneven development resulting in streaks.

How are you processing you film?

 

b.

[ken_burns1]

How were the negs oriented in the drum? Are the streaks oriented along the longitudinal axis of the drum? If so, the problems might be related to filling and draining problems. Or, are they along the circumferential axis? If so, the problems might be related to agitation. At which end of the drum were they located? The end toward the fill/drain spout, or the other end. Were they located side by side or maybe end to end? This type info might offer some important clues. From the looks, this problem is definitely process related, not exposure related.

[leonard_evens]

The film was in a Beseler cylindrical drum, two on each end. The drum is similar to a Unicolor drum, and lots of people use these drums.

 

The drum is placed with its axis horizontal on a roller base which rotates the drum constantly. I use roughly 8 ounces of developer which is poured into a lengthwise horizontal "tray" from an external spout and then the roller motor is started. The film sits the long way roughly against the side of the drum with the emulsion facing inward. As the drum rotates, the film passes through the solution which sits on what is momentarily the bottom of the drum.

 

The bands are roughly perpendicular to the circumference of the drum. From the placement of the bands, it appears that the affected sheets were adjacent to one another, one at one end of the drum and the other at the other end.

 

It is true that some developer slops over onto the film before the roller is turned out, but I always do it that way and haven't had this problem. I developed this film for something like 10 min at 71 deg. I previously used HC110 (B) for times as short as 4 minutes without problem. But perhaps the exhaustion of the developer was an issue. If the developper slopped on the film when filling and then rapidly lost its potency, it could conceivably have led to something like this. Needless to say, from now on I will toss developer kept beyond its recommended storage life.

 

But I still don't find the above explanation very convincing, and I wonder if there is something else I missed.

[leonard_evens]

Another thought occurs to me. I just remembered there was one occasion where I forgot to turn the roller on for something like 30 sec to 1 minute after pouring the developer in. That would certainly explain the bands. I think that was quite a while ago and this film was developed in the last three weeks, but perhaps my memory is playing tricks on me.

[bruce watson]

The bands bend in a way that makes me think that it's not about the developer or what happened in the drum. I would think if it was a developer spill, say, that the banding would be as straight and true as the drum is. These bands seem to bend up the circumference of the drum on their ends.

 

If it possibly a light leak - a bellows leak, like where the bellows attaches to the rear frame maybe? I don't see how actually, but... I'm just trying to think outside the drum ;-)

[leonard_evens]

Hogarth,

 

Am I missing something? Won't a light leak darken the negative film and produce a light area in the positive?

 

I also am suspicious of the developer spill theory because I don't see how it could produce that particular pattern, but I can't think of any other explanation. Perhaps someone else who uses drum processing has seen it and knows the cause.

[gary_meader]

The repeating pattern of these reminds me of a bellows

problem. You said you used a 90mm. Are your bellows in the

way? Happens to me if they sag. Let us know.

[Troll]

I think you were shooting through a wire mesh fence.

[andre_noble4]

Yeah, you may not have noticed the fence on your ground glass, since you were focusing wide open, but the problem will appear once you stop down lens to expose the film????

[bruce watson]

Leonard,

 

No - you are right. I'm the one missing something. I don't see how it can be a light leak.

[ken_burns1]

Leonard, I still think that these streaks are the result of a development problem. These Beseler drums are notorious for streaking problems caused by contamination if the drums aren't washed thouroughly between uses. Do you remove both ends of the drum when cleaning up after a film run? Do you use a seperator rib in the slot that runs the length of the drum on the inside opposite the filler trough? If so, do you remove it when cleaning up? That's all I can think of right now.

[james___]

Either not enough developer, or the film inserted wrong into the drum which would not allow developer to evenly saturate the emulsion. The banding is in pretty much the same place on both samples. Just different degrees of density but in the same places. But this looks suspiciously like exposure to me. I have had similar banding when something wasn't right with the film holder. Are you sure the film wasn't fogged before loading it in the holders? One of the nice things about the drums are the eveness of development. As long as you have enough developer solution in the drum. I vote for a light leak when loading the holders.

[leonard_evens]

Well you people certainly can come up with interesting possibilities.

 

There is indeed a wire mesh fence. It is right there in the scene and perfectly sharp. Sorry, there is no second fence in front of it. The scene is right across the street from my condo, and I see it out my window every day. The garage is slated to come down soon and it and the hole in front of it will be replaced by a large downtown development project. My aim was to record the construction project as it proceded, and this is "ground zero". I will give it another try tomorrow.

 

I use this 90 mm lens all the time, and I've never had any problems with bellows sag. With extreme movements, it would be theoretically possible for the pleats to get in the way, but for that to happen, I would have had to have been using extreme horizontal shifts, which I wasn't doing. You can see from the perspective in the pictures that no extreme movements were used, in any case.

 

I think it must have something to do with development, but I can't figure out just what. But in the future I will use fresh developer and be even more careful about washing the drum.

[leonard_evens]

James,

 

Your comments about how the film was loaded in the drum may be relevant. There could have been something peculiar about it this one time. But I had four sheets of film in there, and it would be strange if two sheets on one sided were misloaded the same way and the sheets on the other side were fine. I do develop film this way all the time, and I haven't seen this particular problem before.

 

As to light leaks in the film holders or elsewhere, I raise the same point I did with Hogarth. Light leaks should have produced dark bands in the negative and light bands in the resulting positive, but I have the opposite.

[tracy_storer1]

Does lining the images up differently contribute to the Bromide drag theory?

The bands then seem to closely correspond to areas of low density on one

neg or the other.<div></div>

[james___]

Tracy, would bromide drag create the same areas of density difference seen here? And if so why would one set be so yet the other not be? He says he processes like this all the time and I doi as well. I have never had this type of problem in processing. Why would bromide drag create the same type problem? Thanks.

[marvt]

In my Beseler drum there is a "rod" that slides in a groove to seperate and hold the sheets in place. It looks as though these two sheets may have been over the rod and not butted up to it. If that was the case the dark band in the image(light on the negative)may have gotten less development, possibly not being deep enough in the pool of developer. This would also account for the over all mottled look of the negative. The mottling being caused by turbulance as the humped up negative passed through the developer. It does look like bromide drag and this scenario would go a ways towrad explaning the problem.

[tracy_storer1]

James,

I'm not an expert on Bromide drag, I've always been a tray guy, except for a

short time with a floated-hand spun Jobo tank. I was just bringing what

seemed like a pattern to everyones attention for further scrutiny.

Best,

[stefan_geschke]

To me it seems that the dark bands are EXACTLY the same on the two pictures.

Doesn't this sort of rule out uneven development?

It looks that there is a systematic error somewhere, not related to the particular picture

taking situation (like a fence) and not related to uneven development.

 

It looks like the phenomenon might also be interpreted as three bright areas.

So maybe this is caused by some light leak/flare after all.

Just a suggestion.

 

Or maybe there was a problem with the production of these two particular

sheets of film.

[brian_ellis3]

Bellows sag in my unfortunate experience shows up as a more or less straight line with a diffused edge at the bottom of the print (top of the negative). This doesn't look anything like that. Light leaks (also in my unfortunate experience) aren't as uniform from negative to negative as these areas are even if as someone else suggested the dark bands are the correct exposure/development and the bright areas are the leaks. Using the dark slide as a shade and inadvertantly getting it in the image area would show up on the top, bottom, or side of the negative, not in the middle.

 

Is it possible that your cable releases are positioned such that they can dangle in front of the lens? Except for this seemingly remote possibility, and given the fact that you've ruled out anything in the scene being in front of the camea, it looks like a development problem to me, not an exposure problem. Unfortunately I'm not sufficiently familiar with the drum system you're using to suggest a specific reason.

[benjamin_lineberry]

Definitely process.

Do you use acetic acid to stop, or a water stop?

 

b.

[randy_becker]

Would a water bath or acedic acid stop be better for this problem?

 

Randy

[benjamin_lineberry]

I've seen people who use a water stop have problems like this with certain developers...

[allen_whittier]

Leonard,

 

Here's something I haven't seen in the post. If your drum wasn't level, it would create a development problem at one end of the tank. Inadequate developer levels would accentuate any flaws in the drum or rails. It could create eddies and your uneven development.