Topic: first try out of Harman Direct Positive

[LT]

Ok - I've had a bit of a mess about with the new harman Direct Positive paper. this stuff is really finicky and is going to take some getting used to.

first test: 5x4 camera with 150 mm lens. exposure at iso 3. the instructions say the paper is very contrasty without a pre-flash to chip off the highlights a bit and gain a greater tonal scale.  Harman recommend doing this in a dark room with an enlarger, but I did it in camera with a total diffusion filter on the front of the lens (eg a Lee gel snap with 3 layers of tracing paper in it)

the first shots I took at f5.6 which gave me an exposure time of 1/2 second.  All were developed in my standard print developer for 2 minutes.

I made three shots, 1 at normal exposure, one with a meter reading minus 3 stops pre-flash (eg zone 2) and one with a reading minus 2 stops pre-flash (zone 3).  All of them came out virtually black, so were madly under exposed.

I did some more reading and found out that Harman used to make the emulsion for the very similar Efke Direct positive paper. So I researched that which suggested the emulsion suffers badly with reciprocity problems at anything less than 1 second exposure (reverse to film).  guessing that this might well be the self same emulsion, I closed down the lens and tried exposing at f8 and 1 second, then f11 and 2, and f16 and 4

the results are below - in order.  Bear in mind all had had effectively the same exposure, and it was cloudy diffuse conditions - unchanging, and all had a zone 3 pre-flash.

some are more contrasty than others, some show better low value separation etc!  It's very difficult to control all of this.  I think my next step will be to stick with the zone 3 pre-flash with an exposure for the highlights at about 1 and a half under meter reading - treat it like slide film, then see where I get.  the finish to the print is exactly the same as ilford MGFB with a bright white base and it has a warmish tone to the developed silver.

(ignore the file names on the pictures, I;ve labelled them in the wrong sequence.

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[Francois]

Does look like it's pretty finicky indeed...
I'm still surprised that the results came out so good...
I haven't checked but am starting to wonder if the paper is orthochromatic... That could change a lot of things...

[LT]

Here's the spectral sensitivity chart - I've no idea how to read these

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[Phil Bebbington]

Leon, the end of that wave seems to mirror what the Greek economy is doing just now! 

[Francois]

This is pretty easy to read. (I had to go to Wiki to figure it out )
The human eye can see light from about 390 to 750 nm.
That means the film is sensitive to UV light but not in the red and infrared part of the spectrum (where it flatlines).
The height of the curve indicates the sensitivity to the color which is on the horizontal.

Here is an image of the visible spectrum

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[LT]

so - looking at that chart you give Francois, the paper is reasonably panchromatic?  seems to cover the blue green and spectrum??

[CarlRadford]

Thats it Leon - looking pretty good, holding tones and detail pretty well. How contrasty was the scene - tonal range?

[LT]

there's nothing in the highlights at all Carl - the scans are probably a tad misleading. It was pretty flat light and about 4 stops of contrast in the key areas  - only the sky in the top corner was beyond this range.

[Francois]

so - looking at that chart you give Francois, the paper is reasonably panchromatic?  seems to cover the blue green and spectrum??

Well... actually it seems the paper is pretty insensitive to red. So it can probably be processed by inspection under a red safelight without any problem. Or under an Ocher safelight if you do the work rapidly.

This means a few things though... it probably is fantastic on portraits since the blood vessels would be invisible... that is if you can get the sitter to stay still long enough (cue Victorian head clamps). It probably also produces nice skies with puffy clouds.

[LT]

the info sheet says you can only use a very feint deep red/ ortho safe light

[Francois]

Not too bad for someone who hasn't read the paperwork

[astrobeck]

was probably designed with portraits in mind, and I should probably move that walk in camera link to this thread?

I would really like to get my hands on a box of this stuff as it looks intriguing for pinhole....can't wait until they make it available in the US!   

[This-is-damion]

Leon, the end of that wave seems to mirror what the Greek economy is doing just now! 

Maybe its connected?  Should we be recycling the paper,  would that save the greeks?

[Francois]

Leon, the end of that wave seems to mirror what the Greek economy is doing just now! 

Maybe its connected?  Should we be recycling the paper,  would that save the greeks?

I don't know... maybe we should start supporting them by eating more baclavas

[Phil Bebbington]

Francois, I'm with you, it's always best to eat or drink your way out of a situation!