With the reduction in Kodak's product line which has lately been decried in other postings, it occurs to me that one possible future victim might be Technidol developer, since it's not exactly a mass-market item. In spite of its expense, it really comes in handy occasionally with film shot in extreme contrast situations.
I need comment from some of the APUGers who have a lot more expertise in chemistry than I have. (Never had a chemistry course, even in high school; I must lead a charmed life, because I also never had to take a statistics course in grad school!)
My specific question--Would refrigerating the Technidol Liquid in its original packaging extend its life? Incidentally, the stuff seems to keep rather well anyway; a few months ago, I used some which was purchased in 1997 and noticed no ill effects. I also assume that freezing would NOT be a good idea. Is that assumption correct?
The Technidol seems to be very long-lasting indeed. It is possible that it will gradually lose its efficiency, so that higher concentrations or longer times will be necessary after some years or decades.
As long as raw chemicals are available, I feel confident that I can make any developer (type) I might need. Powder generally lasts longer than solutions, and can even be refrigerated (which is a bad idea with liquid concentrates).
I don't see Technidol disappearing unless Tech Pan does, and I think there's probably non-pictorial demand for Tech Pan that keeps it afloat (scientific use, archiving, and such). Even if it did, there are formulas like POTA, SPUR and such that could be used with high contrast films to similar effect.
I recently used both the powder and liquid versions of Technidol that I purchased around 1988. The results were just fine, and they were stored in a cupboard in the house.
As David mentions in his post I think the developer would only go away if the yellow gods end of lifed Technical Pan.
If you get the chance try Tech Pan developed for 25 minutes in Rodinal diluted 1:200. You may not want to worry about Technidol going away.
I've used Konica 750 Infrared in Technidol and the results were outstanding compared to what you normally see. My only gripe about the stuff is the expense and the tiny packages it comes in. You have to make two of the little packages up for a single roll of 120. I've never seen Technidol in any larger sizes in liquid form.
The version I have of Technidol is sold in tiny bottles here in Holland. I think one little bottle makes 600 ml. I guess that as long as you keep the little bottles tightly sealed, they will keep for a very long time.
I tried Rodinal once for Technical Pan film, but I did not like it as much as Technidol. As 'Konical' said, it is expensive but certainly well worth the cost.
Hopefully Kodak will keep making Tech Pan film, and Technidol, because it is a lovely film for details in nature.
Thanks to all for the information and opinions.
Aggie--Technidol is used one-shot, so I was only concerned about prolonging the life of the original concentrate.
Ole--Thanks for the advice against refrigerating. A later post suggests that it probably isn't necessary anyway.
David/Mike--I didn't mention in the original message that I wasn't thinking primarily of Tech Pan; I ordinarily use Technidol Liquid for night shots on T-Max 100. Its a perfect combination: a film with favorable reciprocity characteristics and a soft-working developer. I have tried highly dilute solutions of HC-110 and Rodinal for similar exposures, but the results were definitely inferior to those obtained with Technidol.
glbeas/Annemarieke--Years ago, Technidol Liquid was sold here in small bottles, but over here each bottle made 16 oz. (473 ml). I still have a couple of the empty bottles. Currently, Technidol Liquid is sold in a box of six individual foil packets, each one for making 8 oz. of solution. Each box of six costs around $12.00. That certainly makes it a pain in the pocketbook for 120, but I manage 4 sheets of 4 x 5 (in a rotary drum) with only 8 oz.
Found the following on the Kodak website:
KODAK PROFESSIONAL TECHNIDOL Liquid Developer
For producing pictorial negatives with KODAK PROFESSIONAL Technical Pan Films. Produces excellent uniformity with all KODAK PROFESSIONAL Technical Pan Films.
Exceptionally fine grain, high degree of sharpness, enhanced edge effects
Each packet of liquid makes 8 oz of solution (1/2 pint)
For Roll Film—Mixing from Foil Packets; Pour contents into 8 fl oz container. Add water at 68-86°F (20-30°C) to make 8 fl oz (237 mL). Stir until completely mixed. Note: If using plastic processing tanks, diluting 2 foil packets to make 20 oz (591 mL) is possible.
For Sheet Film—Mixing from Foil Packets; Pour contents of two packets of concentrate into one quart container. Add water at 68-77°F (20-25°C) to make 1 quart (946 mL). Stir until completely mixed. This dilution is one-half the working strength used for roll films.
For use in:
small or large tanks
tray (for sheet films)
1 week in a full stoppered bottle
For roll film, 1/2 pint of solution will process 1 roll of 135-36 (developer reuse for additional rolls may apply)
For roll film, 1 pint of solution will process 2 rolls of 135-36 or 1-120 (developer reuse for additional rolls may apply)
For sheet film, 1 quart will process 12-4x5 (Do not reuse this solution for a second batch even if the first batch consisted of fewer than 12 sheets)