Uneven C-41 development

[Ari]

Hi,
I've been using the Tetenal kit for two weeks now, and I've noticed some uneven development here and there, but usually fixable.
Yesterday I got one that was really bad, and I'd like to try and figure out what's going on before processing more film.
I use a Jobo 2553, two reels, twelve sheets of film, on a motorized base.
Pre-soak is at 40˚C (102˚F) for one minute, and I fill the tank completely with water.
Development is 3:30 at 40˚C, and Blix is 6:30 at the same temperature.
I wash for five minutes, emptying the tank at least seven times, then add stabilizer (to which some PhotoFlo has been added) for a minute, and hang to dry.

Most of the film comes out looking good with no issues.
Here's what I got yesterday:


Any thoughts or ideas as to why this is happening would be greatly appreciated.
Thanks in advance.

[Daniel Stone]

looks like the developer streaked.

Try NOT filling the drum all the way, and rather, put the recommended amount of water in. Instead of doing (1) pre-soak, do (2) 30s baths.

I've also found that when using 6 sheets/reel, there's a better chance of mottling/uneven development than if I used 4 sheets/reel, leaving the center slot empty.

Just my $.02

-Dan

[tgtaylor]

I've been developing 6 sheets (color and B&W) at a time using the 2509N reels for years now with no problem whatsoever. As long as the sheets are correctly inserted into each slot you will experience no problems as long as the rest of your procedure is correctly carried out. Jobo has placed two sharp protrusion on the reel, one on either side, that will tell you when and when you don't have either side of the sheet correctly inserted.

A common experience is having one side in its correct slot and the other side in another slot. If this happens then the emulsion side on the top sheet will be against the base side of the other which will result in uneven development. learfn to use the protrusions placed there to avoid this.

Thomas

[Ari]

looks like the developer streaked.

Try NOT filling the drum all the way, and rather, put the recommended amount of water in. Instead of doing (1) pre-soak, do (2) 30s baths.

I've also found that when using 6 sheets/reel, there's a better chance of mottling/uneven development than if I used 4 sheets/reel, leaving the center slot empty.

Just my $.02

-Dan

Daniel,
Yes the developer streaked, but only in one negative out of twelve.
The Tetenal recommendation for drums is to fill the tank completely, but I will try your two-step pre-soak; thanks.
I've never had a problem when loading 12 sheets, so I'll have to discount that theory.
Thanks

[Ari]

I've been developing 6 sheets (color and B&W) at a time using the 2509N reels for years now with no problem whatsoever. As long as the sheets are correctly inserted into each slot you will experience no problems as long as the rest of your procedure is correctly carried out. Jobo has placed two sharp protrusion on the reel, one on either side, that will tell you when and when you don't have either side of the sheet correctly inserted.

A common experience is having one side in its correct slot and the other side in another slot. If this happens then the emulsion side on the top sheet will be against the base side of the other which will result in uneven development. learfn to use the protrusions placed there to avoid this.

Thomas

Thomas,
I've been using this tank for B&W for the last three years, and I've never had problems with streaking development.
My film is properly loaded, I can feel it when loading, and when I take the reels out after the Blix step, all the film is in its appropriate slot, no overlap.
Maybe with Tetenal and 40˚C solutions, it's more important that the emulsion go one way or the other, but again, that hasn't been my experience when developing B&W.
Thanks

*** *** ***

This may be a problem of not having a rotating tank at the time I pour in the chemicals; using a machine such as a CPP or ATL would tell me that for sure, but I see no reason why the method I'm using shouldn't work.
If anyone can chime in with other ideas or similar experiences, I'm all ears.
Thanks

[Daniel Stone]

Ari,

I'd pour your chemicals in while its spinning, try using/making one of these :



I made one out of $3 worth of materials bought from Home Depot(tubing, thicker wall flexible type) and a funnel from the dollar store. Simple, and very effective. I'm no longer doing color at home, since Kodak killed the 5L E-6 kits. But for the occasional 4x5 b/w I soup up in Jobo drums, this is how I "funnel" the chems in while the drum is spinning on the motor base.

-Dan

[Ari]

Thanks, Daniel; great suggestion.
I hope that'll be the end of streaky development.

[Daniel Stone]

Ari,

I found it to be IMPERATIVE that the tank be rotating when doing color(especially c-41, which has a much shorter development time than E-6 or most b/w). Using a tempering bath/pre-soak helps soften the emulsion too, making it more receptive IMO for the developer. But having the film rotating, rather than some of it getting splashed on the sheet(s), the inner diameter of my "pouring apparatus" is big enough to warrant a fast, consistent pour into the tank.

I just put the end of the tube in the end of the tank(I use a geared lid on my 2551 tanks, not the red-cap lids), and hold the funnel with one hand while pouring with the other hand. Works well, and keeps splashing down to a minimum.

-Dan

[Ramiro Elena]

Ari, are those Tetenal recommended times? My kit calls for a 5 minute pre-soak and I think I might have read it was important in order to avoid irregular development (but I might be wrong, I've just started with C-41)
I do 3 minute dev and 4 min Blix on the other hand.
It seems strange that you only got one bad sheet out of twelve.

[Ari]

Ari, are those Tetenal recommended times? My kit calls for a 5 minute pre-soak and I think I might have read it was important in order to avoid irregular development (but I might be wrong, I've just started with C-41)
I do 3 minute dev and 4 min Blix on the other hand.
It seems strange that you only got one bad sheet out of twelve.

Agreed, Ramiro, it does seem strange.
The times are from the Tetenal sheet for Jobo tanks.
I'll try Daniel's pre-soak method, and if it changes nothing, I'll go for a longer pre-soak.
Thanks