HANDLING & CARING FOR ROLL FILM.
This article is by Bertram W. Miller, and is condnsed by Ron Knowles, from the American Bi-Monthly magazine 'Darkroom techniques'. The copy of the magazine was kindly loaned by Major & Rita Pearle, of Colchster. The article points out defects that can arise in the delicate chain of procedures during the handling and processing of film - be it colour or black & white.
A film by the author was, as he puts it, "peppered" with spots but he, fortunately, managed to locate the cause and then correct it. The least of the worries is the acetate or polyester support for the sensitised layers.
Most problems arise on one or both of the coatings applied to either side of the support. One side carries the delicate sensitised layers of the emulsion and the other a layer to compensate for the tendency of the film to curl. Scratching to either side will obviously damage the image.
With modern colour film, designed for high temperature processing, the old bug-bear of reticulation is a rarity. The other major hazard is that of particles embedded in, or adhering to, the emulsion - for these are there to stay. Once the film is dry dust particles which have no adhesive qualities of their own, behave more reasonably for they are easily brushed and/or blown away.
Film comes from the factory in sealed packages, so no problems there. But in our camera there can be dust which can find its way on to the film ... so get rid of the dust! But beware of the awful speck which might lodge in a position where it can scratch your precious original. So be fastidious!
The 35mm format offers even more potential for mishief!! The film will pass through the velvet light trap not once but twice! One to expose and another to rewind. A method of cleaning the light trap is given in the round - a - bout column on page 7.
When processing start with a rigorous vacumming of the work-bench and re-loading into pre-cleaned spirals. Touch the film edges only! The film loaded ... and here comes another source of trouble - water bourne particles. There probably isnt any such thing as debris-free tap water... so the answer here is a filter. Solutions, too, must be filtered especially the first solution used for this appears to be the most critical when first hitting the dry film.
The stabilising bath should be filtered also as the Formaldehyde, as a hardner, may cause particles to be "caught" up in the emulsion. Formaldehyde, because of its chemical activity, has a tendency to combine with air to produce a fine crystaline precipitate - which explains the need to filter the hardner solution.
Hard water supplies may contain dissolved salts, mainly carbonate and calcium which combine with animal fat soaps to form scum. They, in turn, may combine with Colour Developing Agents also forming a scum if not sequestered. However, the sequestering agent, such as a mineral deposit may still be left on the dried film. To avoid the trouble drain off the final wash water, briefly rinse the film and reel in distilled water: then immerse in a stabiliser bath made with distilled water. This, it is said, effectively dilutes the minerals by one million to one.
The writer finally describes a cheaply made drying 'cabinet' consisting of a light wooden frame covered with a fine nylon material with a gentle heat provided by a Nichrome 600-watt element - though, as he says, and ordinary light bulb would do just as well. The dimensions of the frames are given as 40" high: 12" wide and 10" deep.LETTERS....
Dear Sir, having retired about 18 months ago one of my pastimes has been the research and display of family hostory via photography on A/V.
There was a piece of music however, which had always been associated with one member of the family which I was unable to obtain recorded. In desperation, having seen Bert Sander`s offer of music in the C.R.C. Newsletter, I rang him up. No, he did not have that piece of music, but he knew it, and he would see what he could do.
Bert turned up trumps. A short time later I received through the post a tape cassette containing not only the music requested i.e. "The Robin`s Return" but both sides of the cassette were filled with a selection of the world`s most popular classics. The Robin`s Return was unique in that Bert obtained the services of a pianist and this was recorded live. So there you are. In the words of the Post Office "If you don`t use it, you lose it".
Bert assures me that this service is still available to all members.
Reffering to kevin Kraske`s article in the July 90 Newsletter. The newspaper style publication, sadly no longer avaiblable, was "Photo Weekly". This was published around the late 60`s, early 70`s. A regular contribution in the letters column was Fred Harvey who founded the CR50 Club. This was sometime in 1771 as the first News Letter was published in January 1972. (I believe that much later Fred harvey was made Club Presedent).
I still have these Club Newletters and some correspondance and was wondering whether the Club Officers or Librarian have them in their records? I do not have the exact date but I believe the C.R.C. will become of age sometime in 1992.Henry Jenner. (Area 14).
Thank you for your inetersting letter, Henry. We are pleased to report that Fred Harvey, now 82, is living in Essex and though confined to his immediate surroundings, is quite well. I am sure all who remember him will join us in sending our regards and best wishes.
Our Librarian, Eddie Pearce, doesn`t get many requests for Library items, but I am sure he would like to know of any records that you have to offer. Thank you too for kindly offering to transport Mr. & Mrs. Telling too and from wantage for the 1991 A.G.M. at Didcot.Ed.