AREA NEWS
HINTS AND TIPS Patrick Marchmont (Area 20).
ABLE LABELS normally provide six lines on a 2cm label, but they are quite happy to print it twice if you can fit your name and address on three lines. This can be useful where you are limited for space such as on the side of a slide mount.
A POLARISING FILTER may be used in an emergency as a neutral density filter to reduce exposure by 2 to 3 stops, but it does darken the sky.
A HAIR DRYER can quickly raise the temperature of your processing solutions. Give the bottles a "blow dry"!
QUARTZ IODINE projector lamps which become dirty may be cleaned with whisky! On no account use methilated spirits.
SLIDE BOXES Some makes of those slide boxes which are used to return mounted slides (before you took up home processing) will hold four or more 35mm cassettes. Useful for the gadget bag.
SOLUTION BOTTLES If a bottle from a kit has an aluminium seal do not remove this but attack it with a needle or a pin to make a small hole each side. Then it will act as a dropper and the solution will stay fresher for a longer period.
CRC PROCESSING
A number of quiries have been raised about the chemicals used in the CRC home process and the answers have been given below:-
The formula requires EDTA acid in the conditioning bath and EDTA free acid in the bleach. These ARE the same chemical.
The bleach requires 30% ammonia solution. The bleach on the chemical supply list is in fact 15/30% strength. It is apt to Vary in strength according to age and so has a loose classification.
The colour developer and the fixer require EDTA No2. This is entered on the chemical supplies list as EDTA di sodium salt.
The stabiliser requires formaldehyde. The supply list indicates a 30% solution which is the strength required for the chemicals.
When ordering chemicals, if you have suitable empty plastic bottles which you could return to Ron Croad, Please do so as these will be gratefully accepted for dispatching your orders.
BARFEN CRX 6 M. Macdonald Spencer - Area 20.
I`ve just completed a test on the working life of a commercial brew - Barfen CRX 6. The four bath kit is supposed to process 6 lots of 36 shot cassettes only. Each made up solution was divided up into two bottles each of 300ml, so that there were in effect two series of solutions which could be used alternately to process film.
The first and colour developers and the reversal baths were put into 300ml bottles with all the air drive out by Tetnel Protectan and then tightly capped. The bleach-fix baths went into 500ml bottles, so leaving 200ml of space in each: handy for shaking to aerate just before using. The series of solutions were labelled `A` and `B` and were kept in my cold store which never rises above 10C.
Each series was used alternately and an exact record was kept of how many frames gross each were processed, Frames gross are the number of frames length in a cassette. It is the number of exposed frames plus four for the leader and three for the trailer as the chemicals are required to work on the whole length of the film. It is a better measure of the developer exhaustion than counting the number of exposed shots. It can only be a rough guide but it has particular value when processing runs deal with widely varying shot lengths. e.g. a 36 shot, a 12 shot and a 24 shot will add up to 72 shots. But 93 frames gross will have been processed and will have weakened the developers. A couple of 36 shot lengths will add up to 72 shots but only 86 frames gross will have been processed.
Barfen suggest that their first and colour developers have a shelf life of only two weeks, the reversal bath 4 weeks and the bleach-fix 26 weeks. My experiment showed things differently! I made up the solutions on the 14th October 1989 and rejected them on the 12 April 1990! How many weeks is that? All produced pretty good slides.
The 600ml of Barfen chemicals developed roughly the equivalent of eight times 38 shots, not 6 as barfen suggested. But the total was made up of short length cassettes. I think that by using 36 shot cassettes and therefore fewer processing runs, I could be sure of raising my total to eight equivalent to 10 actual cassettes, processed over a six month period. Now that does seem economic to me.