Hi,

Does anyone know how long I can expect Ilford Multigrade developer to keep in a Nova slot processor? Ilford suggest that when diluted 1+9, MG developer has a life of 1 day - but presumably this assumes that the developer is used in an open dish. Does the Agfa MC developer have a longer life than the Ilford brand?

Thanks

Guy Brown

-- Guy Brown (g.brown@dcs.shef.ac.uk), March 24, 1999

Answers

Paper developers are much more active than film developers, and oxidise more quickly, both from exposure to the air, and from use. I would think it would be rare to get more than one printing session from a batch of paper developer, regardless of the processing equipment.

-- Tony Brent (ajbrent@mich.com), March 26, 1999.

I do not know the latest Ilgord MG developer, but I do know that AGFA MC has the longest shelf life and capacity I can remember from the developers I used (Ilford MG ten years ago, Dektol, Neutol, Selectol Soft, Ilfobrom).

-- Lot (lotw@wxs.nl), March 27, 1999.

My experience with llford MG developer is that it is only good for one printing session. One reason I returned to Ethol LPD, along with skin irritation problems.

-- Gene (nikonguy@emji.net), April 01, 1999.

Hi Guy, All developers, print and film, are subject to aerial oxidation and have in their make-up a preservative-typically sodium silphite- to reduce oxidation due to exposure to air and the oxidation products occuring during development. Print developers designed for open dish use, usually from a stock solution, must have good stock solution shelf life, also aerial oxidation as well as oxidation products due to development are clearly greater in dish devlopment than in film development. The surface area of solution exposed to air in a slot tank will be considerably less than in say a 16"x12" dish. Probably in the region of 10 to 12%. We therefore need only consider the keeping properties of used developer and the exhaustion rate due to use. My experience with dish developers indicate that Agfa Neutol and Ilford PQ would give longer life than most among the unpublished formula, and the published Kodak D163 and Geoffrey Crawley's FX12 would certainly do well. There is of course an inevitable loss of solution during use that will have to be topped up with fresh developer: this is a sort of replenishment which helps, and after a printing session the slot should be left full and covered to minimise exposure to air. A friend (who is an ARPS and successful exhibitor of B&W prints) claims 3 months of intermittent use with his 16"x12" Nova tank before seeing a drop in quality. However, it occurs to me that while a drop in quality will let you know when the developer is nearing exhaustion, no such indication will tell you when the fixer should be renewed. It is therefore suggested that you monitor throughput of prints in the fixer, because the visual effects of exhausted fixer is delayed. You and I want to see your prints in the future! Dad.

Clifford Brown.

-- Clifford Brown. (clifford.brown@dial.pipex.com), August 25, 1999.