Heat Stress Or Other?

[hugh_brown]

I have just returned from a challenging week long trip in a remote

part of the Kimberley region of North Western Australia. On this

trip, I was shooting 120 Velvia in my Pentax 645N. The temperatures

were between 47 degrees and 50 degrees on most days (in other words,

the heat was intense). For those in the wrong part of the world, that

equates to WELL over the 100 degrees fahrenheit benchmark - well and

truly over that. Upon receiving my film back, approximately forty

percent of the film looked as though it had been light damaged: that

perhaps, light had gotten in to the edges of the film. The edges of

the damaged film were dark like someone had shot with their fingers

over the lense. Could that be heat damage? I have never had this

problem before with 120. Could the heat have caused the camera back

to expand and so let in light, or could the film itself have expanded

meaning that when it was wound at the end of the roll it constricted

as it cooled down meaning that the film became loose on the roll as a

result (thereby letting in light)? Would be really interested in

thoughts of those

who know about this problem or who have experienced something similar.

What strategies could be employed to circumvent this problem in high

temperatures where weight is a critical consideration on major hikes

like the one we undertook? An esky is not a viable solution (due to

the size and weight). Is it a problem for which there is no practical

answer?

 

HUGH BROWN

[mike_daly]

Hugh,

I doesn't sound like a heat problem to me. You don't say how many films were affected. It does sound like a light leakage problem though rather than a processing problem. I suspect light had entered the magazine during loading or unloading. I find I have to be extremely careful in very bright light loading roll film. Just a glance of very bright light seems to be able to get round the edges of the spool. Not much help I'm afraid! Pity we can't see the pics.

[rolland_elliott]

"For those in the wrong part of the world"

 

What exactly is the "RIGHT" side of the world? I agree that we use a dumb ass measuring system, but your comment above is puzzling.

 

Your problem is not heat damage. Either your equipment is mechanically faulty or your lab screwed it up. If you post some pictures you might get more specific responses, but you don't give us much to go on.

 

Heat damage results in color shifts and casts not light leaks.

 

Peace, Rolland

[brian_c._miller]

Hmmm. If you had a light leak, then the edges would be clear. I have only had this happen with 220 film. From your description, the reverse has happened, the film edges are dark instead of clear.

 

If this happened to all of the rolls, then it may have been due to an error at the processor's end. Maybe you should speak with your processing lab or the film manufacturer about it.

 

When you are out in heat like that, can you take along a small beer cooler? I take a small cooler (plastic foam insulated container) and put ice packs in it with my film. It keeps the film cool that way. Even after the ice packs melt the film still stays cooler than the hottest daytime temperature, and I mean in the desert.

[audidudi]

I live in Arizona, whether daytime high temps in the summer often hit 110+ degrees, and I've never had any heat-related problems with film. I keep my film covered while carrying it in the field and store it in a small cooler inside the car whenever I have to transport it. Maybe I've just been lucky?

 

In any event, light leaks will cause the opposite problem of what you described -- i.e., light splotches rather than dark ones -- so it appears your problem lies elsewhere.

[woodsman]

uh, Hugh, that's 110+ farenheit I believe.

[john_hicks___]

Heat would cause color shifts, probably toward magenta, and fog in the form of (in a transparency film) thin, milky cloudy shadows.

 

I believe you're seeing the result of some sort of processing defect.