120 roll film dries with excessive curve

[steve_wahl]

I'm finding that my rolls 120 Delta 400 (new) are drying

with what I would consider excessive curvature towards the

emulsion side of the film. The curve is an arc which makes

the film look like a quarter of a cylinder sliced lengthwise.

I normally would expect a little bit of curvature due to

shrinkage of the gelatin, but what I'm seeing is excessive

and this is making printing a bit difficult.

 

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I am suspicious of either my process or the low humidity here

in Colorado. My processing uses a Jobo CPE-2: (1) water

presoak for 1 minute, (2) develop, (3) 4 15-second water stop

baths, (4) fix for 3-1/2 minutes, (5) water bath for 1 minute,

(6) hypo-clear for 1 minute, (7) water bath for 1 minute,

(8) bubbling cold water rinse for 10-minutes, (9) hang to

dry with weighed clips and give a good soaking spritz with

distilled water in place of an anti-spotting wetting agent

soak.

 

<p>

 

Anyone have insight as to what is going on and a remedy?

[squareframe]

Steve,

 

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I think this is just a characteristic of the film base. the curl is

far greater than TMY TMax 400 on a 4 mill Estar base. this is one of

the reasons why I most likely will not use this excellent film more.

I cut the negatives in threes, jacket them, and set a plate on them

overnight. it helps, though TMax films are virtually planar out of

the tank which aides scanning.

[Robin Smith]

I find Delta 32000 in 120 does a similar thing. I don't worry about

it, once it has been stored flat for a while it becomes a non-problem.

[georg_kern]

Curling depends on the thickness and hardening of the emulsion. Thick

emulsions with less hardened gelatine (e.g. APX 400) curl very

strong. Films like Tmax 100 are the opposite extreme. The thickness

of the film base and the coating of the "blank" side my also play a

role. In gerneral, it's not a quality criterion, unless you want to

make prints with a glassless neg holder immediately after processing.

[nigel_smith2]

I don't experience this problem with Delta 400. My final wash is a

bath in some bottled water (I think it's de-ionised.. but don't tell

Ed!) with Ilford Wetting agent, hang them with a weighted clip (35mm

one at that so it only grabs the middle section) on the bottom and

let dry.

[how786]

Curling towards the emulsion is pretty typical for LOW hunidity

and rapid drying that it causes.

What worked for me was to get a metal cabinet and place a pan of

water on the bottom. Then dry the film at least 12 hours with

cabinet door closed.

This raises humidity a lot and does away with curling.

Best,

Howard