PROBLEMS MATE!

Compiled by Bill Reid.

In his latest Area 20 Newsletter, Oliver Barron asks the question Why do members get so much varying results while using the same working formulae?". It’s a question worth considering as your editor is now finding out to his cost since getting involved with weighing and mixing after some years of considerable success using many makes of commercial kits.

Considering that these members are all buying their chemicals from him, Oliver wonders why, one member cannot get good results using CD3, but finds CD4 works~ well. Ron Knowles appears to get excellerit results with his 3-bath formula, but a few others have given up this formula because it doesn't work for them. In my own case I got the worst green cast I had ever experienced.

Our Secretary, Ron Croad is getting exel1ent results using his ‘slightly’ modified Arnold Moorhouse formula while others who get good results with one make of film don’t do so with another make using the same brew. Oliver considers that as far as he knows only Charles Myers got successful results using the simulated Kodak formula introduced by the former Area 5 technical bods.

Oliver says that the only common factor to these paradoxes is the Human factor, wrong weighing or even chemicals, wrong temperature or time and possibly, most likely, contamination. Or perhaps "There are gremlins at the bottom of the garden". As it is a serious question Oliver would like to hear from anyone who could give some thought to these problems, as there must be "Some answer".

From his Jan. 97 newsletter I quote here comment Oliver makes regarding Ron Croad using a different pH value, yet gets the results. All official formulae I’ve seen state the pH of the Dl should be 11.6 ± 1. Reg

Cornish has written to me pointing out that Ron’s pH of l1°85 for D2 is away above this and yet he gets first class results. As I cannot fault Ron’s processing. It really is very very good .. then either the higher value suits Ron’s overall formulae and procedure or else his D2 is nearer ii•6 than his measured figure of 11°85. pH meters are queer beasties. This would make it seem that as far as we D. I. Y’s are concerned it’s not worth the cost of buying one, I do not subscribe to this opinion but will compromise and say that if you get a higher or lower value than the generally accepted one and it gives. consistently good results, stick to it, but if you suddenly find a mix giving the lower (correct) one, be suspicious of that particular measurements My own experience is that the Moorhouse with 9 grams per Litre of Sodium metaborate in Dl and 3 grams per Litre of Sodium hydroxide in the D2 always gives me the expected "official". pH value on my home-made meter using buffer solutions to calibrate it either made up to formula from my old Hopkin. & Williams catalogue or using buffer chemicals supplied to me in the old CR50 days by a research chemist working at E. M.  (unquote).

Giving mention to Ron Knowles’ formula, the main problem for most workers has been with the BLIX bath, Hopefully the 2 bath Blix formula that Ron has been given by Bob Fry will assist in curing this. trouble. Your editor, as reported in the Jan. N/L is now getting close to having a working formula In the Arnold Moorhouse brew using metaborate. As the bleach and fixer from the BK6O formula appear to be working very well, it would seem that the problem is in the two developers for one of the reasons that Oliver has stated above.

However this past while there has been much discussion as to how pH values, affect the two developers and there is no doubt that when it comes to. weighing & mixing you need to know that you have got the values a the formula states. But while most of us concentrate on the developers, Bob Lewis has been giving thought to the BLEACH pH value and considering if this too could cause some trouble if incorrect.

Here I quote part of a very interesting article Bob enclosed in his. Feb. 86 News.

"One tends to think that all the bleach has to do is convert all the metalic silver from the first & colour development into silver halides, ready or fixing".

True enough, but can the bleach affect the colour balance of the film? It APPEARS TO BE POSSIBLE, Here is at least one point from the "Basic Photo Science" by W. J. Wall and G. G. Attridge.