U of S | Mailing List Archive | alt-photo-process-l | Re: LC-1 developer question

Re: LC-1 developer question

At 09:46 PM 3/27/2008, you wrote:
Hi David,

I hope it is just a matter of typo, but the LC-1 formula uses sulfite and bisulfite (not sulfAte and bisulfAte). I am not a chemist, but I think they are different, and I used sulfite and bisulfite for my tests.

Dave S

----- Original Message -----
From: <mailto:daviddrakephoto@sympatico.ca>david drake
To: <mailto:alt-photo-process-l@usask.ca>alt-photo-process-l@usask.ca
Sent: Thursday, March 27, 2008 5:22 PM
Subject: Re: LC-1 developer question

Ryuji, what would you suggest adding to raise pH slightly? I have been processing at 75 degrees, but will try higher.
The 'lith' film I have been using recently is a Fuji scanner film HG HSA. I also use APHS but haven't tried with LC-1.

LC-1 developer formula:
part A (1litre solution)
3 grams metol
3 grams hydroquinone
60 grams sodium sulfate
part B (1 litre solution)
10 grams sodium bisulfate

Thanks very much for your help.

This has to be mis-typing. Sodium bisul_fate_ is a very strong acid often used as a drain cleaner. Sodium sul_fate_ IS used in photography, mainly as an ingredient in tropical developers and fixing baths to reduce emulsion swelling. It also acts to retard development. The above formula makes sense if the two are sulfite and bisulfite.
Sulfite is a mild alkali, bisulfit is a mild acid. The bisulfite solution will change the pH, and therefore the activity, of the developer and may be added in various amounts to control the activity. The more bisulfite added the less active the developer will be.
I think Ryuji is right about the needle like crystals being metol. I still suggest warming the solution to see if it will go back into solution. I have also heard that adding about an ounce of rubbing alcohol per liter will help it go into solution, worth a try because if the developer is already no good it can't hurt.
The hydroquinone must be there as a regenerator of the metol because it is inactive at low pH as it is in D-76. Metol, OTOH, will develop in even a slightly acid solution. Kodak D-25 is a fine grain developer which is buffered to neutral pH and uses metol as the sole developing agent. FWIW the formula for D-25 is:

Water 750.0 ml
Metol 7.5 grams
Sodium sulfite, dessicated 100.0 grams
Sodium bisulfite 15.0 grams
Water to make 1.0 liter

Use full strength for extra-fine-grain development. The film should receive about one stop more exposure than for D-76.
When diluted 1:3 D-25 becomes an acutance developer, delivers full film speed but looses its extra-fine-grain property.
Note that this is D-23 plus the buffer.

Richard Knoppow
Los Angeles, CA, USA