My packet of paper arrived Friday
I have spent the weekend experimenting with this paper.
One of the first things I tested was my safe-lights. I found that, despite being 'red' and safe for every other paper I have ever used (except Kodak Panalure, obviously) they are definitely not safe for Harman Direct Positive paper!
A Photax dome type "A" with a 15 watt bulb over four feet away shows visible fogging effect after 30 seconds. I've posted a few test strips I made in the technical gallery. The Ilford recommendation is a '906' filter. I don't know what this is, but it is clearly a much deeper red than my standard darkroom lights. I'm going to try taping a wratten 29 (ruby red) filter over a torch, later today, I'll report back.
The surface of the paper is very pink! My first few test strips came out as black and pink images... my initial reaction was to increase fixing time and agitation, which made no difference. Extended washing is what it needed. The Ilford Technical Information recommends 60 minutes for fibre based paper, which would no doubt take care of it, but I have the RC version, so expected a much quicker wash (I'm only doing test shots, so I'm not interested in archival quality). Well... a quick wash does NOT do the trick.
I used the paper in various plate cameras, mostly quarter plate. I standardised on an exposure of 2 seconds (following Joe VanCleave's advice - I'll worry about reciprocity later...) and a development time of 2 minutes in Ilford Multigrade developer. The weather has been a bit miserable - cloudy and overcast. Consequently the scenes I photographed were very flat, low contrast with no shadows. EV values were around 10 to 12 so I was mostly using f11 and f16.
My first few images, without pre-flash, had very hard soot and whitewash type contrast. I made a lot of test strips to find a pre-flash time that would give just give a noticeable change in density (no longer fully black) then backed off a little. On my set up this meant 6 seconds on an Opemus 6, 75w lamp, 40 cm above the baseboard, no filter, f22. This gave a focussed image of 14" X 14" (I defocussed it to make the flash).
The result was a dramatic change in density - at the expense that nothing in the picture was fully black any more. Consequently it was all a bit muddy. I reckon the paper speed comes out at about ISO 6. Later shots I halved the pre-flash. This allowed me to produce black again, but the contrast again became very harsh and the I reckon the image was about a stop under-exposed (down to about ISO 3).
Next I tried a soft working developer. I mixed up some Ilford ID3 - which is very close to Kodak D165. This tamed the contrast, but only by preventing the paper from producing a proper black, as with the max pre-flash. The edges of the print, where the paper was unexposed, were a couple of zones short of true black. I then tried 30 seconds in Ilford multigrade developer, followed by 90 seconds in ID3. This got back my black edges - but the print was still a bit muddy with no true blacks in the image. Much work to do, yet!
So-conclusions so far:
1. Standard red darkroom lights are not safe.
2. The paper does respond to different developers to control contrast.
3. Pre-flashing also controls contrast, but I haven't yet managed to get a satisfactory print using pre-flash and full development in Multigrade developer. Sufficient pre-flash to get the contrast into a suitable range prevents the formation of a true black.
4. Paper speed approaches ISO 6 with a max pre-flash (just short of recording a tone) , ISO 3 with half that value.
I've posted some images in the technical gallery.