Contrast control & color printing

[bill williams]

Sterry and C-41

PE,

The ferricyanide and bromide were in solution in 500 ml of water as that is what the tank holds, and they were used prior to the C-41 developer. The article I read indicated that the carry-over from the .1 percent solution of ferricyanide on the film would not pose a problem to the C-41 developer.

The same technique used on the film would be used on the paper, that is to bleach it after exposure but prior to placing it in the developer.

I've not yet used my C-41 developer after having used it for the developement of the bleached film. I might be in for a suprise when I develope my next roll of film, but I'm hoping that the Darkroom and Creative Camera Techniques article was correct.

 

[bill williams]

Sterry and C-41

PE,

If I implied that I placed the ferricyanide in the developer I didn't do it intentionally, as it was indeed in a bath that was used prior to the C-41 process.

 

[Photo Engineer]

Bill;

Sorry, my fault. Yes, I agree with you now. Used as a prebath with a good wash or a clear and wash before development will reduce speed and contrast.

PE

 

[stevewillard]

The ferricyanide and bromide solution sounds interesting, and I am curious about its application to reducing paper contrast. Clearly this approach to managing paper contrast is not applicable for roller transport machines which is what I use. My Fujimoto CP-51 would not allow me to presoak the print in the solution because there is a paper sensor at initial entry used to determine paper size so that the baths are properly replenished. Wet paper would damage the sensors.

If pre-bleaching paper can reduce its contrast will it also reduce the color saturation of the paper? One of the reasons I use the paper I do is because of the beefed up color saturation it offers to compensate for underdeveloped negatives. If this attribute is compromised then I would not be interested in it.

Is this pre-bleach process controllable? Can I apply the bleach for a certain amount of time to get a predictable reduction in contrast? For example, 3 minutes of bleaching will yield a one stop reduction in paper contrast, while a 5 minutes of bleaching will result in a two stop reduction in paper contrast?

Does pre-bleaching compromise the archival qualities of the paper or film? Will the film or paper fade or experience color shifts prematurely? Anything that undermines the stability of my materials is not an option for myself or my patrons.

 

[Photo Engineer]

Adding 1 g/l of Sodium Sulfite to the RA developer will lower contrast and Dmax. You may not like the results. You can go up or down from this central value.

Prebleaching does not affect dye stability materially, AFAIK.

PE