What color filter to use with a paper neg pinhole?

[snay1345]

I am thinking about making an 11x14 pinhole camera. I have a 4x5 pinhole that I use, but I use sheet film with that so I can use my regular black and white filters. But with the 11x14 i will be using paper negs and contact printing back to positive. The only question I have is what color filter should I use. I am wanting to try and get the paper neg to print like how a regular black and white photo would print when using a yellow or red filter during the time of exposure. Any help would be great.

 

[RalphLambrecht]

If a paper negative is properly exposed without filtration, the shadows have plenty of detail, but the highlights are far too dense to make a decent print from it. The reason is that modern photographic paper is not designed for this application. It is designed to create a positive image by reversing the tonality of a relatively low-contrast negative.

A ‘normal’ scene has a subject brightness range of 6 stops from the deep shadows of Zone II to the bright highlights of Zone VIII. This is not a problem with film negatives, which can handle exposure ranges of up to 15 stops or more, but it can be a problem with paper negatives. Exposed to unfiltered light, variable-contrast (VC) paper has an exposure range of only 3 1/2 stops, and if the exposure for a normal scene was metered for the shadows, the highlights are doomed to block up.

Nevertheless, with appropriate filtration, the exposure range can be significantly extended. Green (G11) and yellow (Y8) filters, typically used to enhance the contrast with film negatives, extend the paper exposure range to about 6 stops. I recommend the use of a yellow filter, because it requires less exposure correction to achieve a similar effect.

One can also reduce the developer concentration to successfully control paper negative contrast. My standard paper developer is Kodak Dektol, diluted with water to a 1+2 solution. My paper negatives, however, receive a yellow-filtered exposure and are developed in a relatively weak 1+8 solution of Dektol for the entire standard duration of 90 seconds. The resulting negative has a 3 1/2-stop density range and prints well on a grade-2 paper.