I was unable to find any information on this on the web. The
manufacturer has a web site but it only displays various
developers. Its on the giant developer chart (drawing a blank on
its right name).
My guess is that the PQ means phenidone hydroquinone If so
that might make it similar to Ilford Microphen. Microphen is
similar to a phenidone version of D-76. I think Ilford has a
published formula for something similar but can't remember its
number off hand. Microphen is a good, general purpose, fine grain
developer which in comparison to D-76 delivers slightly finer
grain and slightly higher speed. I am a bit puzzled by the
dilution. For Romek its given as 1:3. So either its more
concentrated than Microphen or is a different developer. Ilford
does give instructions for Microphen diluted to 1:3. At that
dilution is becomes a high definition developer. Actually, D-76
does too. Kodak does not give times for 1:3 but Ilford does for
ID-11 which is identical. I've tried it and get a very strong
edge effect but don't like the way it looks.
AFAIK, the patents where they ever existed for all these
developers has long expired so anyone can make something like
Xtol, T-Max, Microphen, Microdol-X, etc, etc.
Several modern developers use Phenidone in place of Metol and
ascorbic acid in place of hydroquinone. Generally, Phenidone
yields slightly higher speed than the metol equivalent.
Back in the 1930s C.E.K. Meese, the founder of Kodak's
research lab, said that the great number of developers only
showed how many ways there were of doing the same thing.
Also, those of us in the U.S.A. have the advantage that we
can buy nearly anything even despite some EPA regulations where
in other countries there are import restrictions or other barriers.
On 12/15/2020 1:17 AM, CarlosMFreaza wrote:
Hello Louis:
Thank you. I like B&W very much, anyway I also like to shoot color sometimes. Romek PQ7 is a developer manufactured in my country, the factory info about this liquid developer is basic; it's an ultrafine grain developer on the basis of an element they call "phenimek", I guess phenidone, an Ilford trade mark. I use it because I like the results most of the time and it's available here regularly, at least so far; I have used several other developers like Agfa Rodinal, D76, both Tmax, Perceptol, Microphen, Tetenal Ultrafin Plus, I liked all them, but some of them are not available here sometimes or they become more expensive due to the exchange rate, therefor I'm using the PQ7 from some time ago. There is some additional info and feedback about the PQ7 from users, but most in Spanish.
I liked your photographs at Flickr, nice light and good contrast.
Carlos
