CD2... The Versatile One!

By Ron Knowles. Area 11.

A colour developing agent which has been pushed into the wilderness of recent years has suddenly emerged with renewed vigour, among some members and Areas of the C.R.C. until comparitively recently CD3 has been the most universal choice of home brewers but now I can reveal at last some advantages of CD2, neglected as I have said, until Oliver Barron. Leader of Area 20, obtained a supply and invited members to try it.

Well I can state with absolute conviction that this agent used with the original Arnold Moorhouse formulae will give VERY acceptable results, given normal care, with any of the current reversal films.

Whilst CD2 is not, so far as I`m aware, available from any of the usual chemical suppliers I understand Oliver Barron has a fair stock which will enable members to use it in their colour developers for the foreseeable future.

With CD2 I found the frames just a trifle more contrasty than with CD3 but otherwise everything about the results was pleasing. Colour saturation was intense, sharpness appeared enhanced and the blacks - well black!. There was not, on any of my tests, a hint of a colour cast. All of which was confirmed by Oliver himself and other members including Tony Chuter, Bill Reid, Roy Johnson and Mr. & Mrs. Pearle.

The formulae, as I`ve said, is the Arnold Moorhouse as originally given though I have added extra Sodium Sulphite to D2 to extend it`s keeping qualities.

Ph is adjusted by adding Sod. Hydroxide to move the pH up. Or Sulphuric Acid to move the reading down. In each case use a dilute solution of 10% adding a very small amount each time until the correct reading is reached.

STOP BATH

NOTES

(1) The pH value for the first developer given here as 9.6 is the original figure given by Arnold Moorhouse. I found that a slightly higher figure of 9.8 preferable. The pH value in the first dev. affects only it`s activity and does not upset the final colour.

(2) As mentioned I have added Sodium Sulphite to the Colour Developer. The quantity is 5.0gm. replacing the 2.7gm. in the original formula.

(3)The time for the First Developer is as given - 6 minutes. If however the frames are all dense increase this to 6« or even seven minutes.

(4) Should the frames be excessively contrasty it is suggested that the amount of CD2 in the Col. Dev. is reduced to 0.6 or even 0.5gm. It will be found that this colour developing agent is extremely versatile and works very well over a fairly wide range of concentration.

(5) Reversal was a photoflood - 3 minutes each side within a distance of 12 inches ... after removing the film from the spiral. If the film is left in the spiral this time must be increased by at least 50% for a clear plastic spool or up to double for the transparent type.

As always with reversal processing great care is necessary with temperature and timing for the First Dev. as the density of the film at this black and white stage controls the final density, colour balance, contrast and quality of the blacks.

PROCESSING PROCEDURE

An advantage of the high temperature used in the E6 process is the fact that the washing times are so much shorter then in previous processes.

My own method is to use around One-Litre jugs of water, which fills my tank about twelve times. After filling I shake it vigorously, empty and fill again. This takes less time than it sounds and I find the method extremely sufficient. The reel can be removed from the tank for washing following the First Stop Bath. Again this tends towards efficiency.

May I finally, suggest to members who have not been having all the success they could well have expected from weighing and mixing to try this - somewhat dated - formula once again... but this time with the CD2. I'm more than sure you will not be disappointed. And I`m equally sure Oliver Barron will be happy to find his supply of Cd2 is not only getting less but is also being put to good use.