Using Harman Direct Positive Paper with Studio Strobes

[scottnichol]

i've used harman's paper in the past with natural/continuous light with good results. recently, i had an idea to do something more experimental with it and attempt to shoot a model in motion. the idea was to shoot 4 different exposures with the model in a different pose each time. each exposure would be on the same piece of paper and each time the shutter release is pressed, two alien bee 800 studio flashes will fire. i thought this might be enough to create a nice multi-exposure image.

however, when i tried this over the weekend, after i developed the sheets, the result was just a completely white sheet. no image at all. thinking about this as a positive paper, it almost seems like it is over exposed. however, you don't even see the black border from the film frame. this makes me think that perhaps it didn't get anything near the exposure it needs to make an image.

the first test shot we made, i did at f/8 with a 150mm lens on my 4x5 camera. going with the theory that it was over exposed, i tried again at f/16 and f/22. same results - full 4x5 sheet of white after development. each sheet was flashed for about 1.5 seconds under my enlarger.

has anyone tried this before with any kind of luck? i thought i would ask before continuing to use up additional sheets.


thanks
scott

 

[Maris]

The result of developing unexposed Harman DPP is black. If you get white the paper is grossly over-exposed or the developer is dead. Harman DPP needs strong developer to give a decent black. I use fresh warm Dektol 1+2.

Pre-flash amount is critical, +/- 10%. I give 0.8 seconds at f16 under my 4x5 enlarger with the (empty) negative carrier 900mm above the base board. Your calibration will differ. I always pre-flash with the Harman DPP in a film holder. The edge rebate delivers a reference maximum black to compare to the other tones.

Ordinary safelights will disasterously fog Harman DPP and deliver white frames in the developer. I use a very dim deep red safelight.

 

[wildbill]

I suggest you get a light meter.

 

[scottnichol]

The result of developing unexposed Harman DPP is black. If you get white the paper is grossly over-exposed or the developer is dead. Harman DPP needs strong developer to give a decent black. I use fresh warm Dektol 1+2.

Pre-flash amount is critical, +/- 10%. I give 0.8 seconds at f16 under my 4x5 enlarger with the (empty) negative carrier 900mm above the base board. Your calibration will differ. I always pre-flash with the Harman DPP in a film holder. The edge rebate delivers a reference maximum black to compare to the other tones.

Ordinary safelights will disasterously fog Harman DPP and deliver white frames in the developer. I use a very dim deep red safelight.

i was using very fresh Ilford Mulitgrade developer. i'd just mixed about 10-15 mins before attempting to develop the first test shots. in my previous attempts at shooting this with continuous light, the prints developed fine (tho i used Ilford PQ Universal developer that time). so, i think i had the developer down and there was no fogging from my safelight setup.

i'll experiment again this weekend, hopefully.

 

[scottnichol]

I suggest you get a light meter.

thanks. i was using a light meter along with my best extrapolation down to ISO 6.

 

[bracan]

Few Harman DPP portraits unflashed

Harman Direct Positive paper unflashed rated 1,5 iso. Developed in Ilford Multigrade developer for 3 min. Taken with Sinar P 8x10 and Rodenstock 300mm f5,6 Sironar wide open.

 

[bracan]

More Harman DPP portraits

 

[NB23]

Seriously good stuff, Bracan!