mystery image

[ann]

One of my students developed 20 rolls of film the other night.

Tonight he was making contact sheets and viewing them with an eye for printing.

One roll has very strange "markings" . It looks like someone pre-exposured the film using lizard skin instead of blue sky. then went back and exposed typical shoots. Mostly vacation stuff but nevertheless things he is interested in.

THe first thing that came to mind was reticulation, but this is unlike any I have ever seen. Although after 50 years of woerking in the darkroom I haven't seen it happen more than once or twice

All film was developed at 68 degrees and the wash water might have gotten to 71 but he is an advanced student and is very careful.
I also find it hard to believe that if the temperature had shifted, it only effected one roll.

I wish I could do a better job explaning but lizard skins is the best description of the pattern. It is very weak , but easily seen with a lupe and of course no problem with seeing it on the print.

Any thoughts would be appreciated.
Like to avoid this happening again.

 

[Mateo]

I've had a similar result shooting in hot humid Florida. It was from condensation on the film when it's exposed.

 

[Annemarieke]

Could it have anything to do with x-ray machines in airports? I have heard of strange patterns appearing on film for that reason. Not just fogging, but actual patterns.

 

[JHannon]

Was this seen on all frames or just a few at the start of the roll?

 

[Shesh]

I have had a similar pattern appear on the film once while developing quite a few rolls in a single day and this was the explanation I came up with: I was probably not careful in throughly washing the tank after the previous rolls were rinsed in the washing aid. Subsequently, during development of the roll in question, the remaining wash-aid seems to have created froth in the tank during agitation and I ended up with this pattern.

 

[mvjim]

Without seeing it, it sounds like developer foaming. It could have been caused by photo flo on the reels or excessively agressive initial agitation. Some developers foam more than others. Are you developing in tanks or dip and dunk? I doubt if it is x-ray damage as this usually shows as waves ~~~ of uneven density.

 

[ann]

this pattern appears on every frame, altho, it has a somewhat different form. But very much a pattern, not streaking as one would find with over use of a wetting agent. Or water streaks from a lack of a wetting agent.
I am unable to scan it and send it along but perhaps next week I can have him make a print , scan it for me and then forwarded it along for viewing.

The tank was a Patterson, 8 reel tank. This only occurs on 1 of the 20 rolls of film.


I would think the x-ray exposure whould not have such a specific pattern, but we have not had that problem (yet).

 

[Shesh]

This does sound like the problem I had. Was he using Photo-flo?

 

[BobF]

Unless the pattern is different from one sproket side to the other I can't imagine it being foaming as the bottom area will still have liquid and only the top might get foaming. With agitation (hopefully) the bubble pattern would change and just cause underdevelopment on the foamed side or maybe just the top reel as this is an 8 reel tank.

 

[ann]

He was using photo flo, but I will have to check to see if he remembers if this roll was on the top.
The pattern varies from frame to frame. I can't say from one spocket side to the other. The only sameness is that there is something strange going on on each frame. More random in nature may be a better way to describe.

 

[dr bob]

Do you instruct students to use wetting agent in developer?

 

[ann]

No, no wetting agent in the developer and no pre-wash.
I have been doing darkroom work for over 50 years and haver never seen anything like this. Surely keeps me on my toes.