It seems to me that the main function of
Citrazinic Acid is to destroy the ‘gross excess of colour developing
agent, until the quantity remaining is just sufficient to produce the
right amount of dye in the right places. From heresay or from print, the
information I have is that it destroys something like 50 - 75% of the
developing agent and without being precise, each Litre of developer
results in the chemicals neutralising each other at a cost of £1.50 or
Why pour costly chemicals down the sink?
The pH values of the developers Mr.
Cowling gives as 12.41 for the first and 12.76 for the colour. The
readings taken 24 hours after mixing and prior to dilution. Three month
old samples had virtually the same pH as the current mix.
So it was to the darkroom for me to try
out this concoction for myself - and, maybe, or others opt there as .well.
So I made up the two developers with only a couple of differences from Mr.
Cowling‘s. I omitted the Calgon as I always use distilled water. The
Genochrome was substituted for AC7 as the chemical has been unobtainable
for many years. Otherwise I followed Mr. Cowling’s formula to the
minutest details. As I did, too with the processing procedure being
particularly careful to maintain the 100 degs from first to last.
But I 1 fear the first strip was a total
disaster - the frames. had a VERY severe green cast and the actual image
was, DECIDEDLY “thin” with only the faintest suggestion of red and not
a trace of any other colour.
Then I adjusted the pH values to the
more conventional ones - First Dev. 9.9, Colour 11.25 and carefully
processed a further strip. This time the green cast was just; as
pronounced though the image had far more contrast and bore SLIGHTLY more
of the reds, blues and yellows.I concluded that there was little point in
wasting more precious film. It seems to me that Citrazinic Acid is a
necessary ingredient - though the exercise was worth while if only to
remind me of the futility of trying to cut corners when dealing with
colour film.
THE CROAD CONNECTION
Since
completing this copy for my HERE & THERE column I have received
information in regards to a query I raised in the April issue regarding my
own particular ‘hobby-horse”. pH values of , especially, the
two developers.
In that issue I suggested that Ron Croad
of Area 20 might like to let us have the pH values of his mixes ‘and he
,has kindly done so through his Area Leader, Oliver Barron. The values
are: First Dev., 8.75. Colour Dev. 11.25.... ( note, these figures have
been changed to Ron’s latest information as reported on page 3 of the
July Newsletter.. Ed.).
C
.R. C. AREA INFORMATION
How useful it would be if a breakdown of the .Areas were is
sued to members together with names and addresses of Leaders. I for
instance have no idea where Area 19 is. If I had, and also the address of
the Leader, Reg Long could have been contacted direct. This, I believe
would provide an additional and valuable link - all helping to hold the
Club together.
==============================
It is my pleasure ‘to have received
the latest “HERE & THERE” from Ron. It arrived after I had
compleyed the July Newsletter and so include it as an additional piece as
Ron Has already started on bits and pieces for the October Newsletter.
A full C.R.C. Area Leader and Committee
list appeared in Issue No, 25 and there was an update of changes some time
later. However, Ron must have been reading my mind as there has been a few
changes over the last few months and I had it in mind to give a list in
the October issue, so for those interested, watch out for that.
The aim of the club is for members to be
able to make contact with fellow members and exchange news and views from
any Area to another. However, while I can give you the Leader’s
addresses, you must contact them for any individual member’s addresses.
Editor.