From: Sandy King (sanking@hubcap.clemson.edu)
Date: 01/04/01-09:47:01 AM Z
Marc,
MQ == Abbreviation for a paper or film developer that combines the high
contrast developingagent hydroquinone with low contrast metol. M stands for
metol, Q for hydroquinone. PQ is a combination of phenidone + hydroquinone.
PMK == Is a pyrogallol/metol staining developer (P=pyrogallol, m=metol and
k=kodalk), developed by Gordon Hutchings and introduced around 1990. Widely
used in the USA by many who appreciate the unique printing qualities of
stained negatives/
ABC+ == Is also known as Rollo Pyro, a more energetic version of PMK
formulated by the Austrian photographer Harald Leban several years ago. It
is much better than PMK for rotary processing (eliminates the high b+f
stain PMK gives in this application) and is much prefered to PMK when you
need to develop negatives to the high denity ranges we need for most of the
alternative processes, or for zonal expansion. Both PMK and ABC+ are
makketed widely in the USA but the formulas for both are known and they may
be easily mixed from scratch.
Sandy King
>Helloooooooooooooooo,
>
>Thanks for the quick answer. Because my english is just my third language I
>have some problems with the abbreviations :
>
> MQ developper
> PMK
> ABC+
>
>Can you help me please ?
>
>See you,
>
>
>Marc (Belgium)
>
>> Hello, After working with a 8x10 inch camera ... I am thinking
>>about going larger. I developped the 8x10 sheets in hangers I bought in a
>>shop several years ago. But for larger formats I cannot find something
>>usefull here in Belgiumų (Europe) !!!!!!!!!!!!!!! So here we go with
>>some questions : How do you develop larger formats such as 11x14 or 8x
>>20 ? Which developper is used at this new method ? Thanks ... have a
>>nice 2001 ..... Marc (Belgium)
>
>
>Marc,
>
>You have two practical choices, 1) develop the large film in trays, or 2)
>develop in tubes with rotary processing, using either film drums or tubes
>(BTZS, home-made tubes. or Jobo expert drums). The method you use would
>logically be governed by the quantity of your work. There is no question
>but that tray processing is more productive so if you need to develop a lot
>of sheets in a single session this is the best way to go. I prefer rotary
>processing and have various drums and tubes that allow me to do either one
>or two sheets of 7X17 or 12X20 at a time. My preference for rotary
>processing is guided by the fact that, 1) with all considerations I believe
>it is the single *best* way to develop film, 2) rotary processing in tubes
>on motor base leaves me free to do other things during film processing, 3)
>I hate to stand in the dark for long periods of time doing nothing but
>scratching my derriere and shuffling film, 3) I am incredibly adept at
>scratching and making deep gouges in the film during tray processing.
>
>As for developers you can go with either an MQ developer or a staining one.
>D76 straight or D76 1:1 is popular and favored by many large format
>workers, as are the staining develpers PMK and ABC+. I will also recommend
>my own Pyrocat-HD formula, a staining develper based on
>Pyrocatechin/Phenidone. It is less expensive to mix than PMK and ABC+ and
>works in place of either of them: a 1:1:100 dilution of Pyrocat works
>almost exactly like PMK 1:2:100 (both in terms of development times and
>curve characteristics), while diluted 2:4:100 it replaces ABC+ (and is even
>superior to it for zonal expansion of tough films like BPF and HP5+).
>Pyrocat also is much less likely to stain film than pyrogallol based
>developers lier PMK and ABC+ which must be used with rotarty processing
>with great care.
>
>Sandy King
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