120 Process Problem

Hi all,
Every time I process a roll of 120 film the last three frames are always wiped out, looking like they've suffered massive light leaks and being completely ruined. I think this is a problem with my processing as whenever I have had a colour rol processed at the lab it comes back fine - my black and whites are the only problem. Does anybody know why this might be? Up until now I could live with it but as i'm about to do a wedding i'd hate to lose 3 shots per roll. Thanks very much.

Is it the same film mag? Are you loading complete darkness? Plastic tank with light leaks? (don't laugh, I had an old Ansco plastic top that had a lighter black color in one area and it used to let in just enough light to fog the film.)

That's all I can think of.

load a roll of unexposed film in your tank and processed as you would and see what you get.

Passing thought ...

Is the messed up end on the inner end of the tank spiral?

If so, could this be a tank that needs a baffle or stirring rod or whatever installed on/in the center of the reel to block the light? (I seem to remember there are/were some tanks like that.)

DaveT

DWThomas said:

Passing thought ...

Is the messed up end on the inner end of the tank spiral?

If so, could this be a tank that needs a baffle or stirring rod or whatever installed on/in the center of the reel to block the light? (I seem to remember there are/were some tanks like that.)

DaveT

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If it is a Patterson tank, you definitely need the center post if you process in the daylight. This is true for 35mm and 120.

Mark Fisher said:

If it is a Patterson tank, you definitely need the center post if you process in the daylight. This is true for 35mm and 120.

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I's also possible it's the wrong centre column, the are two or three centre columns that are close in size. Old Syten 4 & New System 4, and there were two older tanks one a uiversal that takes one 35mm,120 (1279, the other a multi that takes 2x35mm or 1x120.

So if there are multiple tanks around it important to make sure you have the right centre column for the tank.

Ian

Thanks very much for the advice everyone. The baffle thing sounds very promising as i'm pretty sure it is always the three/four shots at the center of the roll. I've tried different tanks so i've ruled faultiness out at least. I'll give that a go, up until now i've always though all that piece of plastic did was help the agitation! Cheers!

it's not the stirring rod, to be clear, that is needed. it's the center column. All paterson tanks, and their copies, have a center column. The reels slide onto this column. The whole shingdig then sits on a little spiked hub-thing on the bottom of the tank, then the funnel-top goes on top, then the lid, ultimately. It is that center column that makes it light tight.

It wouldn't happen to be due to the film being loose on the take-up spool, with the film getting fogged when the camera is unloaded?

What brand film are you using and where did it come from? Sounds like some of the problems you might expect when buying ultra-cheap and/or bulk-loaded films.

I've had the same problem with a bunch of films but i've mostly been using Kodak TMax100 or Ilford FP4 Plus125 so i'm sure that's not the problem. The fact that I haven't been using the center column that keeps the whole thing light tight sounds pretty promising! Cheers

kaiyen said:

it's not the stirring rod, to be clear, that is needed. it's the center column. All paterson tanks, and their copies, have a center column. The reels slide onto this column. The whole shingdig then sits on a little spiked hub-thing on the bottom of the tank, then the funnel-top goes on top, then the lid, ultimately. It is that center column that makes it light tight.

Click to expand...

This is a gripe I have. The Paterson tank is a superb piece of design; I believe it is in the MOMA design collection, for good reason. However, there is one thing wrong with it, which wouldn't be a problem for most of us, but for beginning students it is.

The lid is black. This suggests that if you are using inversion agitation you should be ok without the column. Students go in the dark, have trouble loading, put the film back in the tank, put the lid on and come out to get help. Film is fogged. The culprit here is the red plastic strip that goes around the top, that the lid fits on. It radiates red light in the tank. I am sure that for the little people who live in those tanks, the quality of light is lovely. But it ruins the film, and at their stage, students need success, not failure. Of course, doing that once usually takes care of it. To make the light trap work requires the center column and the funnel be assembled just as if the reels were in it. The only function of the lid is to keep the chemicals from falling out.

So one student got interested in this and called the distributor to ask about this, the answer came back "It has no function other than as a decorative accent".

Clearly, the committee which inducted the tank into the MOMA collection did not include a basic photo teacher in its membership.

They could have made that strip black and included a red stripe somewhere else on the tank. They could have made the lid a translucent red, so it would be obvious that light would be admitted.

I had that problem - my college had these new system 4 tanks - I found the lids leaked and the bayonetted funnel top came loose if inversion-agitated too roughly, leaving the film wrecked and me wearing the developer! Why they ditched the old design I'll never know - it's far more practical and easier to use. Also the lids are white or grey, so they're not light-tight.

One of my old S4 lids has a sticker with 'Selected for the Design Centre, London' on it.