Effect of Filters on Harman Direct Positive Paper

[Fragomeni]

Hi all. I've read a few past threads regarding the new Harman Direct Positive Paper and people's efforts toward controling the contrast of the paper. I, like many others here, have had good luck working with yellow (and similar colors) filters to control contrast when working with paper negatives produced using variable contrast papers but these techniques don't seem to work for everyone when using the new Harman DP paper since it is a fixed grade paper as opposed to a VC paper. Now, despite many people saying that the yellow filter trick doesn't work with this paper, I've seen examples shot through yellow and orange filters to do show an effect on contrast (assuming no flashing). I'm just curious to hear exactly what results people are getting (and maybe see some examples) by shooting the paper through various filters.

Also, since the paper is highly blue sensitive I would assume that shooting through a filter that changes the color of light hitting the paper would indeed have to have an effect on contrast and image rendering. I'm hoping that someone will be willing to take the time to explain how changing the color of light effects this paper and precisely why.

Thanks for the insight and I hope I'm not rehashing too much thats already been discussed. Thank you!

 

[Maris]

Harman Direct Positive Paper is orthochromatic with some sensitivity in the yellow part of the spectrum.

I use a orange filter when taking portraits with this material. This avoids the rather ugly rendition of skin tones that orthochromatic materials tend to deliver. The orange filter I use costs 1.5 stops on panchromatic film but a lot more on Harman DPP. Before exposing Harman DPP I preflash by giving 1 lux.second worth of tungsten light from an enlarger.

In my skylight studio I set Harman DPP at EI = 0.6 on an incident light meter and shoot with more hope than confidence. So far the results are ok but I suspect that other lighting systems, flash or tungsten, would demand different EI values.

 

[Fragomeni]

Thanks for the information Maris. I've seen some good results of ortho materials shot though orange and red filters. I'm very curious as to what different color filters will do. I know a few collodion photographers who shoot through blue filters. Collodion is orthochromatic as well and in these cases shooting though blue filters makes for shorter exposure times and seems to improve overall contrast since it makes all of the light hitting the emulsion blue and the emulsion reacts more evenly across the image as opposed to shooting filterless. I haven't heard much about anyone trying this with the DP paper. In the end, this will probably come down to me experimenting with it but so many people here have great insight that I know will help move along the progress.