RA-4 Printing, Color Cast and Filtration

What causes the need to adjust filtration to get correct color ?
So, given proper exposure with proper light temperature ( day light film in day light) and dichroic filters manufactured to a given standard, why are things not as simple as dialing in the given filter pack and printing away ?

What variables come in to play ?

Thanks,
Charles

In reply to your question, where do you want me to start? All the following can affect colour balance. Assuming you have the correct filtration for one negative the things that may make a change in filtration necessary.
1. Different film stock (Fuji - Kodak - Agfa)
2. Over/under exposure
3. Age of the developer
4. Changing the make of developer and condition of concentrates (Different batch numbers)
5. Inacurate mixing of working solution
6. Temperature consistency of the developer
7. Paper type and different batch numbers
8. Make of film developer
9. Over/under development of the film
10. Age of the enlarger bulb. As it gets older the light emitted changes colour towards the red end of spectrum
11. Slight contamination of developer with blix

There's few to be going on with.

Thanks for the reply, I really appreciate it.
Now back to the darkroom to get better at color correction and printing.

Thanks,
Charles

To simplify things stick with one film (or film family), one batch of color paper, one brand of processing chemicals, and shoot a gray card or other reference every time the light changes (or your location changes) and make calibrated contact sheets. You'll get to the point that you can eyeball changes in filtration with the aid of a set of Kodak Color Print Viewing Filters on the contact sheet faster than you can analyse the negs in the enlarger. Using an incident light meter will also help with exposure consistency (one less variable).

I will go along with the Kodak Print viewing filters to assess colour balance. Mind you the factors given in the wallet holding the filters for colour adjustment do not equate with Fuji paper neither do the exposure factor calculations to give the correct exposure with FUJI paper, Fuji paper is quite a bit faster than the Kodak currently being produced. However they are a very good guide.

I haven't had any issues using the Kodak viewing filters with Fuji papers, I can
match a gray card quickly using them, YMMV. But everyone's set up is a little different as BMbikerider pointed out.

I also shoot a gray card for each type of film I am using, but not for every light condition. I shoot it in the middle of the day in light shade because I want to balance for midday color temperature. That way when I am shooting early in the morning or at the end of the day I get an accurate rendition of that warmer light right off the bat. Do what ever works for you (darkroommike has his, I have mine), but getting those gray card shots makes it really easy to dial in both color and density fast.

I agree with btaylor, no need to shoot a grey cart at each light condition, just one at the correct condition for that film. Then you can decide wether to correct or not color cast from different light temperatures.

As already said by others there are many things that may influence colour balance. It would be nice to know what actually is the exact colours on the negative once one could cancel the orange mask, perhaps if I'd calibrate my colorstar analyzer to null the film base I'd get the real colours?

When Kodak was still cutting and packaging color paper, the box would have a recommended starting filter pack. In my experience if you were shooting a Kodak professional film like Portra, and using a (In my case Beseler) dichro color head, it was really close. Now its Fuji Crystal Archive(thanks Fuji!) for cut sheets. No recommended starting pack. Still once you get a pack it's pretty stable.
I really enjoy printing color its so easy once you balance the filter pack, optical printing blows away the quick LED prints you get from minilabs
Mike

Well, neither Kodak or Fuji sell cut sheets these days, what you find is re-packaged by someone else. You can also buy cut sheets of Kodak paper, at least here in Europe. I buy rolls anyway since it's cheaper and not difficult to cut in the darkroom. I use Kodak endura premier F and if you check the data sheet Kodak gives a starting filter pack which is sort of accurate

Berri said:

Well, neither Kodak or Fuji sell cut sheets these days, what you find is re-packaged by someone else. You can also buy cut sheets of Kodak paper, at least here in Europe. I buy rolls anyway since it's cheaper and not difficult to cut in the darkroom. I use Kodak endura premier F and if you check the data sheet Kodak gives a starting filter pack which is sort of accurate

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Kodak is not available in cut sheets in UK. So if FUJI is re-packaged by someone else, it is very well done because it is in FUJI boxes and packets! I will go along with the Kodak version (Far better paper in my view). I am on my 2nd roll of 12" wide x 88 Metres long Kodak Glossy after getting totally fed up with FUJI paper. I found Fuji incredibly hit or miss to get a correct colour balance consistently sheet after sheet. By that I mean, if you get the correct balance for one negative and print it, and then print a second from the same negative, the 2nd will be noticably different from the first. In addition the FUJI paper seems to be on quite a flimsy paper base compared to to Kodak

Before I started to use rolls of Kodak paper, I was concerned about light getting to the roll once it was opened, so I designed a simple paper dispenser into which I placed the roll and fed the paper through a narrow slot at the bottom. This was 'dispenser' made from a 10mm x 5ply wood sheet with a lid that fitted snugly over the top and lined with black velvet material and the roll of paper was supported by wooden roller which rotated in 'V' shaped bearers inside . The emulsion surface of the paper faced downwards so the bottom edge of the dispenser was also lined with black velvet. Externally the paper slot was made light tight with a simple lid that was also lined with black velvet.

To cut the sheets, I use a 350mm wide roller paper cutter (about 14") and place this at the base of the dispenser and an A3 sheet of card is fastened to the opposite edge of the cutter and is marked with common paper sizes. Under the light of a dim DUKA/Kaiser safelight I pull the paper off roll to the length/size I need and just slice it off. Although I can cut almost any size I need, I usually only cut 3 sizes, 5", 10" and 16". The 5" is usually cut down to be used for test strips. The 10" and 16" marks give me a 10"x12" and 12"x16" size sheets.

I usually cut a few sheets of the size I want and store them in a plastic paper box, large enough to take a full size 12x16 sheet. Before I finish, I fix a piece of adhesive tape to the non emulsion side of the paper and wind everything back into the box, leaving the end of the adhesive tape outside. I use this to pull the paper out of the slot the next time I need to cut more. The light tight lid is then replaced and the paper stored until the next time.

Comparing the price of a roll of 12" wide x 88m long Kodak paper to the price of cut sheets of FUJI I have calculated that I save somewhere around 75% of paper costs. The only downside to this is, when I am coming towards the end of the roll the paper has quite a strong curve and has to be cut a few days before use to give it a chance to flatten out.

The quality of Kodak has to be seen to be believed, if you get the colours all in balance they almost seem to jump off the paper - they are stunning!

BMbikerider said:

Kodak is not available in cut sheets in UK.

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don't know in UK, but you can buy it in Germany

BMbikerider said:

it is very well done because it is in FUJI boxes and packets

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I think they make those in Germany as well. I agree that fuji paper is not as nice as Kodak, I use rolls too but 20,3cm wide x88m it last me a long time and the paper is very good quality, heavy and shiny! I was thinking of making a dispenser too, but then it was just another project I never made, bloody deadly sloth

Yes, basically you can use standard filtration and exposure times for your enlarger and filters and print away if you are producing consistent negatives. This typically means daylight light for daylight color film; using the same film and paper; consistent development of the film (an advantage of doing your own); and a consistent procedure in your print making.

But once the light (color temperature) changes for a particular shot; you use different film or paper; and film and print development are not consistent (e.g., chemical freshness, temperature control), changes in color filtration and exposure time are needed. However, the standard conditions are still useful to follow; they will usually get you close, typically requiring only one additional print once you get experience and a feel for what corrections are needed.

My whole past life in printmaking was enlarger colour prints... 60 Yellow 40 Magenta is always a safe way to start , as well a well defined Ring A Round will solve all issues..Yes I know I keep talking about Ring A Rounds, they are time consuming to make and a bit tricky so most people find it not worth doing.. For me it saved my ass and kept my job as a colour corrector for about 15years of my professional life.