COPYING COLOUR PRINT AND PICTURES ON COLOUR NEGATIVE
By Bill Wilson (Area 22/17)
Making large colour prints from small colur prints without the original colour negative is not easy, where quality is concerned. My early efforts were "try again". I suppose like most people I believd what I read in articles of the photographic press, which glibly told you most of the errors would be compnsated for by various filters which would ensure correct results. My trouble started when I found this was not so; and I decided to find out why. I should mention I used to make my own colour prints, but decided it was more economical to let someone else do them for you.
To start with I took a set of four colour negatives, and the results in a day from your local D&P shocked me with awful colours, compared to the original colour print. I compared my set of home processed colour negatives, to those from a professional lab; and there was a difference in contrast, gradation and appearance. The formula used was C41 from the B.J. of Photography. There followed another set of colour negatives, of the same subject with altered apertures, using brolly flash, with the shutter speed to suit the flash.
After processing, the density on two negs looked promising, but the four prints from the local D&P were still poor in relation to the Pro. Lab. for those of you with B&W skills it was still at Gamma 0.75. The only suspect and the weak link in the CD4. I then made up a set of four negs each of colour developers CD3, Cd2 and Activol 7 (Johnsons) this carries the same chemical base as Genochrome (M&D) Activol 1 (Johnsons) and S28 (3M).
The results were startling, from the prints of the D&P Labs, and the winner was CD2 and with a close match the negs of the labs, with colour and contrast close to the copy print. A test for a good negative being to draw a diagonal black line on white smooth matt paper. Place the neg over it. If you cannot its over exposed and the print will show this. If you can see the black line very clearly the negative is under exposed. I have seen prints from D&P Labs and if you think the machine will correct all this, you`ll believe anything.
This is the modified formula I used, weighing out carefully, without a pH test. I get rain water for all my work from a 50gall. plastic butt. I also use a pre-soak. Film used was Fuji 100ISI.
| Pre-soak. | Grams | 45 secs. |
| Calgon | 0.6 | |
| Sodium Sulphite | 1.5 | |
| Pot. Bromide | 0.4 | |
| Sod. Carbonate | 9.0 | 3 mins |
| Hydroxylamine Sul. | 0.6 | |
| CD2. | 0.75 | |
| Water to make. 300ml. |
You may need to shoot an set of exposures to find the best combination to suit you. Details of my set up are: Flash 80G.No. fired into a 32" Dia brolly at 4'-6" from copy neg at 45* Deg. Use a matt white reflector on the opposite side. Shutter and Aperture to suit. Height of brolly to suit height of copy neg. When making an exposure, keep the view finder blanked off. Some cameras are equipped for this by small lever at the side.
It is preferable to 'PULL' Developer, but do not 'PUSH' at all. From an economical point of view, the quantity of CD2 is about half that for CD4. and Pot. Carbonate has been replaced by Sod. Carbonate. Shooting in strips of four negatives is necessary for D&P Labs. After your forth exposure, do not wind on, but in total darkness open the back of the camera, and carefully taking out the spool of film, cut film about 'half-an-inch' from the felt tip of the cassette, press in the rewind button, and withdraw the film. Load it into the film tank for processing.
Give Ron Croad a bell, he'll be pleased to sell you CD2. I shall be trying out XP1 & 2 with the above formula.
Bill Wilson. Area 22. Tel. 0703-616139.* * * * * * * * * * * * * * * * * * * * * * * * *
F R E E O F F E R ! ! !
The aptly-named German company, Kaiser, have issued a supplement to their accessories catalogue listing additions to their range of copying and lighting units - as well as B & W and colour enlargers.
The advertisement in Amateur Photographer invites applicants to send a cheque for £2.95 for a FREE copy! - As Sir Winston might have said... 'some FREE copy - some flaming cheek!'.A. R. K. BARGAIN OFFER !!!
Did you FALL for that GREAT offer in the National Press by Dixons, for £60 trade-in for your old Camera, for a brand new electronic/digital box of tricks, at over £300, and at almost 40% interest re-payment? - OUCH!!
Would you trade in your 10/20 year old Canon or Olympus for £60!!, and feel sure that it wasn't included in the price anyway!!.