Pre-flashing Direct Positive paper from Ilford Harman

[Megrez]

I am proposing to use Ilford Harman Direct Positive paper in my half plate camera.

Does anyone have experience of doing this? If so how, and for how long, do you pre-flash the paper to reduce the contrast, prior to the main exposure?

I have read the information sheet produced by Ilford Harman, but this is not making much sense to me! The notional speed of the paper is 3 ASA. Is there a formula to decide what % of the metered exposure should dictate the pre-flash exposure time?

Kind regards,

M

[jnanian]

hi megrez

i wish i could help you, but i haven't ever used efke or ilford's direct positive paper.
i poked around for you, and still came up empty ...
when i make conventional paper negatives i sometimes preflash my paper
to just before it is visible on the paper ... that is like .2 seconds stopped down a little bit ( maybe f8? )
i also use a developer that is partially used, and a water bath, and a developer that is "fresh"
and i go between the 3 baths for a good 2-3 minutes ... i am not sure how the direct positive paper
works if it is a vc paper, or something like " grade 3 " ... but these are tricks i learned just having fun.
i also expose in non-bright/contrast scenes/portraits ( read-- flat light ) so there isn't too much trouble.
the last paper negatives i processed i did so in caffenol c spiked with a little bit of print developer.
the caffenol was old+ used and i used IT in conjunction with the fresh developer and water and it turned out great !

you might try a few different methods with "test strips" so you don't use up all your
paper doing test exposures that didn't work the way you wanted ...

good luck ! i have wanted to try it, but my lack of funds has kept me away from it
seeing it might be addictive + more fun than my wallet wants me to have !

john

[Maris]

I have shot a lot of Harman Direct Positive portraits and controlling it is a slippery business indeed. Here's where I'm up to:

I use a 2 stop orange filter for portraiture to overcome the truly vile ( coarse, ugly, contrasty) orthochromatic rendition of skin tones. My effective EI is 1.5.

Preflash is critical. I use 0.8 seconds under a 4x5 enlarger (150 watt lamp) set high with f16 on the 150mm lens. A preflash of 0.7 seconds or 0.9 seconds is different not only from the point of view of contrast control but the EI of the paper changes too! Testing and optimising for your own system is the only way forward. My first 50 sheets were "wasted" in testing.

Preflash reduces the capacity of Harman DP to deliver a decent black. I use warm fresh Dektol 1+2 to get as much density as I can.

Fixing is demanding. Weak fixer will leave a nasty magenta stain in the paper. I use Hypam 1+4 fresh and warm.

Exposure is deadly critical. 1/3 of a stop makes a visible difference. During a portrait session I have an assistant running to the darkroom with exposed sheets and calling out corrections as the shoot progresses.

Harman ostensibly produced this material as a resource for pinhole photographers. With the limited control available in that genre of photography I cannot see how anyone can get predictable results. In the studio with everything under control Harman DP can yield unique camera-original pictures.

[Megrez]

Dear jnanian and Maris,

Thank you both for your detailed replies. You have given me a great starting point. I am grateful to both of you.

Many thanks,

M