What do YOU think happened? Reticulation anyone? ?

[brucemuir]

Hey guys and gals.

I finally assembled all the needed components and read everything I could find on the black and white reversal processes. Although this first attempt was using the "Ilford Process" I gained vailuable info from quite a few regulars here on apug. Thanks, you know who you are.

Okay take a look here http://http://www.flickr.com/photos/brucemuir/sets/72157622875693837/ on my flickr if you would. Film was expired TMX (2007)

I followed the Ilford instructions to the letter (almosy haha) except for the bleach. I used 55 g/l of sodium bisulfate in place of the sulfuric acid. All other parameters were the same per Ilfords instructions.

I have 3 things that I think could have caused the emulsion to peel in the way it did.

1. Permanganate Bleach too strong (I followed the formula except for the bisulfate)

2. Heat-I did a light reversal with a "drop light" type thing that you work on cars with. It has a reflector, I think I may have gotten too close and heated the edges of the film.

3. Rinse water was too cold. It was around 10 degrees colder than the rest of the process.

I inspected the film after the bleach step and the emulsion looked "creamy yellow" and was intact then.

I noticed the emulsion came off after the fix and not before.

What do you people think happened?

 

[Ian Grant]

Your temperatures must have been way out . . . . .

Ian

 

[brucemuir]

The process temp was 20C


What I'm thinking is the shock of the heated edges from the light reversal and then the colder rinse did it.

The exposures dont look too bad I don't think, at least for a first try.

 

[Denis K]

Whatever you did, I think your web_L3M8111 image is really neat. It speaks to me about life.

Denis K

 

[trexx]

I have had similar results doing reversal, but not so dramatic. This is where a hardening fix would be useful. Also keep the temperatures consistent. that may be a water bath for all chemistry.

 

[brucemuir]

I used Kodafix and I didn't notice the problem til after the fix step.

We had a cold snap here a few days back and i didn't temper the rinse cycles. The tap is usually close to 20c and when I was doing it I said to myself, "ah, 10 degrees isn't that much and I think hot water is what causes reticulation". It was in the back of my mind.

I will try again and be more consistent.

I have a boatload of expired TMX so I'm fortunate in that regard.

 

[Photo Engineer]

This is not reticulation. It is the actual separation of fully hardened film from the support by destruction of the subbing layer or bond with the support.

This usually happens when the pH is out of line or the temperature is constant but wrong (too high).

I would use a hardening fix next time around. And, use sulfuric acid instead of Bisulfate.

PE

 

[nickandre]

That is really cool! I've heard it happens with reversal processes when the film doesn't like something about the chemistry.

 

[Photo Engineer]

This is what happens regularly when you coat on the wrong side of film support with no subbing to grab the emulsion. It also happens when there is no subbing. I've seen this and done it often.

It also happens a lot with glass plates.

All you have to do is harden the film emulsion properly and skimp on the interfacing of the emulsion to the substrate. It can take place with paper as well but is more rare.

PE

 

[brucemuir]

PE,

are you suspecting the film was coated improperly? ? ?

Like I said this was out of date Tmax 100 and I was hoping to standardize on it first (i have a few 100 ft rolls I got cheap) before I tried some other stuff.

This film has performed fine with regular negative processing.

 

[Photo Engineer]

No, not at all.

The process was the problem here. You can prove it by processing a piece of the same film in its normal process. If it survives, it proves that the process was at fault.

OTOH, if the film does the same thing, then the film was defective.

PE

 

[brucemuir]

Yea, I always regarded TMX as a "hearty" emulsion. That it would handle the permanganate assault.

The sulphuric acid is a problem, I know I can it get from the formulary but it is a hassle (DEA forms, ID's faxed etc) and expensive.

I've seen were people said the sodium bisulfate could substitute without problems.

I'm banging off some test frames now as we speak and I'll try the whole process again using closer temp control.

I also have some stannous chloride that I can try later for the reversal step.

 

[Anon Ymous]

...The sulphuric acid is a problem, I know I can it get from the formulary but it is a hassle (DEA forms, ID's faxed etc) and expensive...

Car battery fluid is usually 30-35% sulfuric acid solution. Go to the nearest gas station and have a look; concentration might be written on the label.

 

[Ian Grant]

The Dichromate reversal bleaches are far better than using Permanganate as they have a hardening effect on the emulsion, whereas the Permanganate bleaches cause appreciable softening.

Ian

 

[grahamp]

It doesn't sound like a heat problem.

The usual light reversal recommendation is to keep the film immersed in water in a white or steel bowl. Clear reels help, but even Paterson white reels will work with enough time. With steel reels you have to unload the film. The water serves to avoid overheating the film and reel, and makes it possible to reload the film if it has to come out of the reel. Obviously you do not want to splash water on the hot bulb!

 

[brucemuir]

UPDATE

I ran a second roll and monitored temperature closely. Although the emulsion remained intact, there is an uneven density probem that doesn't look like bromide drag,

I'm not sure if it's an issue with the reversal exposure or an agitation problem.

Image is here
http://www.flickr.com/photos/brucemuir/4191116247/sizes/l/in/set-72157622875693837/

Click "original" above the image for larger view.
I'll get a better scan of one frame shortly.

Any thoughts?