Chris, I have compared pinhole paper negatives with and without a yellow filter in front of the pinhole, and have found that the filter reduces contrast and improves the tonal range of the negative, making contact printing much easier. The positive prints still have an orthochromatic look because only a portion of the visible spectrum is being used.
The paper, of course, has to be variable contrast paper which will yield a lower contrast image in response to yellow filtration. (This is just the opposite effect of a yellow filter producing more contrast with panchromatic film.) The filter also blocks UV light to which the paper is sensitive. Blue and UV light can overwhelm a paper negative if you are shooting at altitude or at the seashore. Your use of a #0 contrast printing filter may give 'better' results than the K2 or #8 camera filter I use because the #8 is a cutoff filter whereas the #0 will allow some blue light to pass. I'm considering the permanent installation of a #0 in the next camera I make. Bob Chris Harkness wrote: > A while ago I placed a 0 contrast filter behind the pinhole of my 11x14 > pinhole camera, in which I use 11x14 Ilford MGIV RC paper for negative > material. > > It SEEMS to me that the tonal range of the negative improved. However, I am > not at all sure of this. > > I know I could run some test and find out, but was wondering if anybody had a > definitive answer. > > Many thanks for your thoughts and info! > > chris
