LIBRARIAN`S COMMENTS

Brian Asquith.

Firstly. Please note, my address was shown incorrectly in the Library advert on page 16. (this has now been put right. Ed).

Likewise I omitted to mention that the author of the Colour paper Formula for EP2 and RA papers (CRCN 69, pages 8 & 9) is Tom Amos, a friend, who deserves the recognition for this work.

I have received little response to the Library`s services. However I am continuing to add to the list of available books. The American Photo Mag has nothing in it on reversal processing. One or two interesting articles mainly to do with control of printing B&W. Also a run down of all the photographic papers available, in America of course, though we can get most of them here and some like the Kentmere range are not included.

The Kodak book the club purchased is a mine of information on copying. To do this job properly is not easy. This soft back book is full of tips and illustrations of how its done. Lots of references are to Kodak materials but other makers films could be used.

I got "Photo Pro" which is a good read for the more advanced photographer. This and a few other magazines are in the library and available to members.

TO FILTER OR NOT TO FILTER... AYE THAT`S THE...

When mixing the reversal bath for the Club formula I am left with residue of white substance in the mixture which refuses to mix. Very much like the precipitate sludge when mixing high speed fixers for B&W. In that case you can pass it through a filter paper and make it reasonably clear and it does not affect the use. In commercial kits i.e. Chrome Six, the reversal is in the colour developer, no floating sludge there. In other kits I have had, the reversal bath has been lovely and clear. So what`s the answer? Should I filter, does the sludge effect the keeping properties and its use? I seem to remember a formula which did the reversal in the colour developer as per Chrome Six, this did not use Propionic acid. It could be simpler perhaps to try and find it and give it a try.

This `sludge` is probably due to using such `fresh` raw chemicals and it doesn`t appear to affect the reversal bath, in use. I too have been tempted to possibly filter this bath, but I have also, always, been very wary of filtering, as you never know if you might be filtering out some useful minerals etc, that could affect the working of the `bath` or cut its useful working life. The only real answer is to "give it a go" and find out for sure, but I doubt if any affect will be found.

P.S. Three bath (Commercial) kits most likely use the very dangerous TBAB chemical for reversal, which the CRC formulae avoids altogether.

Ed.