This one dilution looks funny...

[Alex.the.KoNE]

Hello all,

This is my first post on APUG! Looks like a great community whose knowledge I'll be able to tap into! For those interested, I'm a cinematographer based in Montréal, Canada. I shoot a variety of formats, some digital (off an old 10D and a single 50mm lens), some color 35mm, reversal, B&W, but mostly medium format and soon 4x5 thanks to somone's stepfather who sold his Crown Graphic on Ebay!

So, here's my problem. I've mixed some 500mL Ilford MG Paper Dev from concentrate at 1+14 around Christmas (about 8 months ago) and stored it in a transparent 625 mL glass wine bottle I corked. (Yes, as in oxygen permeable cork, that's probably it.) Now, I just mixed another 1500mL at the same dilution and they are both of a VERY different colour.

The old dilution is a very dark amber.
The new dilution is pretty much clear.

Dead Link Removed

I know it's also been intermittently exposed to sunlight.

I'm pretty sure it's dead by now. Anyone would care to autopsy the contents? Why did it turn such a color?!? Oxydation? Is paper developer photosensitive?

EDIT: BTW, I just ordered a few one liter amber glass jugs with airtight polypropylene caps, so it shouldn't happend again or if it does, I won't be able to see it.

 

[Rick A]

Definitly looks like oxidation-- try it before you toss it I have some dektol that turned brown, but still useful.
Rick

 

[fschifano]

That's normal for general purpose paper developers. Once diluted down to working strength, the shelf life is not very long. Ilford recommends no longer than a day in open trays, up to 24 hours if stored in a tightly stoppered bottle. Your saved working solution in 8 months old, so I'm willing to bet money that it is quite dead by now, and that the dark color is due to oxidation. The stuff may be somewhat sensitive to light, but in my experience, not terribly so. I store all my developers in clear plastic PETE soda pop bottles. These bottles are gas impermeable enough and have good tight closures so there are no problems with oxidation. I do store them in the darkroom, which is naturally dark most of the time, but don't worry about room light. If I stored the stuff on a sunny window sill, I might reconsider. Here's Ilford's tech sheet for their paper developers. Everything you need to know is in there.

 

[Alex.the.KoNE]

A day!?! Wow... thanks for the info.

 

[Chazzy]

By the way, welcome to APUG, Alexis.

 

[fschifano]

A day!?! Wow... thanks for the info.

Yep, that's about it. Ilford is probably being very conservative with that number though. I use Dektol, which is similar though not identical. If I've run only a few 8x10's or equivalent through a fresh working strength batch, I'll pour it back into a bottle and it's usually good for a couple of days later, but no more and the overall capacity is somewhat diminished. The first signs of developer exhaustion will present as an elongation of the time it takes for the image to show the first signs of development. Before long, the developer will become so weak that full development will not be possible leaving you with weak blacks and lowered contrast through the middle values.