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Thread: Harman Direct Positive Images

  1. #21
    JoeV's Avatar
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    Re: Harman Direct Positive Images

    Okay, so what about using the Harman Direct Positive paper in pinhole cameras? Well, because of its slow sensitivity (my calibrations show an Exposure Index of 1.6), even in direct sunny bright conditions you'll have long exposure times, depending of course upon your pinhole camera's focal ratio.

    The first image attached is a daylight scene of the old Aztec Motel sign on Central Avenue in Albuquerque, after they recently tore down the building. Sunny conditions, mid-morning light. The exposure time was over a minute, as I recall. Having a wide angle camera that produces some corner darkening, as in this image, helps the image, I think.

    The second image posted is a self portrait under bright daylight conditions but with some high, thin clouds that softened the light somewhat. As a result of the paper's slow speed, the diminished light and the pinhole camera's large focal ratio, the exposure time was around 7 minutes.

    So, although using the Harman direct positive paper in pinhole cameras is entirely possible, and results in good images (see the Aztec Motel sign), it can quickly become impractical when the light starts to dim.

    ~Joe
    The photograph and the thing being photographed are not the same thing.

  2. #22

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    Re: Harman Direct Positive Images

    As might be suspected however, double dark slide (dds) is distinguished from the single dark slide (sds) of the past.
    http://www.earlyphotography.co.uk/site/entry_B13-2.html
    and here
    http://www.earlyphotography.co.uk/site/entry_B26-1.html
    Bill
    "There are a great many things I am in doubt about at the moment, and I should consider myself favoured if you would kindly enlighten me. Signed, Doubtful, off to Canada." (BJP 1914).

  3. #23
    Maris Rusis's Avatar
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    Re: Harman Direct Positive Images

    Quote Originally Posted by Maris Rusis View Post

    Old-time Photographer

    Gelatin-silver photograph on Harman Direct Positive Paper 8x10 exposed in a Tachihara 810HD triple extension field view camer fitted with a Fujinon-W 300mm f5.6 lens.
    More on "Old Time Photographer" illustrating the desperate measures invoked to get decent photographs out of Harman Direct Positive Paper.

    There is very little picture generating technology involved in "Old-time Photographer" but there is a lot of sneaky subject management and studio wrangling hidden in the back story.

    The subject is me in costume as a tatterdemallion photographer. Because Harman Direct Positive is a very short scale material I dressed in grey to avoid empty shadows and hard highlights. Direct Positive is severely orthochromatic so coloured clothing can deliver bad tonal response surprises. Grey garb sidesteps the problem. The tatty T-shirt with the white pattern came out well. I guess the result is "shabby chic" or the next level down from that.

    The black beret prevents "chrome dome" glare. The "granny spectacles" are a contrivance to put metallic glints near the eyes. The mid-grey studio backdrop is on the back wall but my other backdrop, a brilliant white, is actually on the studio floor to kick light up and keep luminance ratios under some control.

    The main props, camera and tripod, were chosen for the bright metal-work accents. These blow out to featureless white but the areas are small, the eye accepts them, and they liven up the picture.

    Exposure was determined by trial and error starting at an assumption of EI = 6. I would make an exposure, walk to the darkroom, and process immediately, and then re-shoot. Development goes to completion in a couple of minutes so I know what adjustments to make for the next shot.

    Pre-flashing is the key to taming this recalcitrant material.

    I use one of my 4x5 enlargers set to 950mm high, 150mm lens at f16, 150 watt bulb in the lamphouse and 0.8 seconds set on the timer. This delivers an actual pre-flash exposure of about 4 Lux.seconds (if my luxmeter is accurate). Your set-up will surely vary from this but trial and error and persistence always win. After the paper is loaded into the 8x10 holders (dim red safelight) the holder is centred under the "pre-flash" enlarger, the dark-slide pulled, and the 0.8 second blink is given. With the dark-slide back in, the holder is carried up into the studio for trial exposure in the camera.

    Pre-flash is a critical quantity. I find results at 0.7 seconds and 0.9 seconds are solidly different from 0.8 seconds. A confounding factor is that a change in pre-flash seems to cause a change in the the effective speed of Direct Positive. The only way through this nest of variables is continued experiment. My first 50 sheets of this expensive material went on exposure and pre-flash tests! Exposure is critical. Even +/- 1/3 stop makes an obvious difference. I've had all my shutters electronically timed (to the third decimal place) and all lens apertures calibrated to avoid bad surprises.

    A nasty consequence of pre-flashing is the loss of a proper black tone. The picture edge in "Old-time Photographer" didn't get any pre-flash and it shows a good black but nothing in the picture area actually matches it. That's the trade-off: control contrast but kill black. A partial compensation comes from using fresh, strong paper developer. I actually warm the Dektol 1+2 to get maximum activity. Development goes to completion in about two minutes. Direct Positive is demanding of fixer. I use fresh Hypam 1+4 warmed a bit for 5 minutes.

    The orthochromatic response of Direct Positive delivers vile (harsh, ugly, gritty) skin tones but I find that a 2 stop orange filter improves things a lot. The downside is that the effective EI is down to approximately 0.6. Very slow indeed!

    Mysteries still unexplored include the effect of illuminants of different colour temperatures. I suspect daylight is not like flash is not like hot tungsten. And I haven't tried to work out the reciprocity characteristics of Direct Positive. It may be that Direct Positive actually gets "faster" with extended exposure times. I just don't know.
    Photography:first utterance. Sir John Herschel, 14 March 1839 at the Royal Society. "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..".

  4. #24

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    Re: Harman Direct Positive Images

    Maris,
    Thanks for all of that.

    What is that background material made of?

  5. #25
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    Re: Harman Direct Positive Images

    Wow, makes me wonder what on earth makes the stuff worth all this?

  6. #26

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    Re: Harman Direct Positive Images

    Roger,

    I was thinking the same thing, then I remembered how long I struggled with APHS Ortho and Kodak Imagelink films. Sometimes a challenge is enough.

  7. #27
    Roger Cole's Avatar
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    Re: Harman Direct Positive Images

    Quote Originally Posted by Jay DeFehr View Post
    Roger,

    I was thinking the same thing, then I remembered how long I struggled with APHS Ortho and Kodak Imagelink films. Sometimes a challenge is enough.
    Good point. People could ask us the same thing about LF when MF or even digital is good enough for 90% plus of our actual uses (or at least, for mine, I just like shooting LF.)

  8. #28
    Maris Rusis's Avatar
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    Re: Harman Direct Positive Images

    Quote Originally Posted by Tom J McDonald View Post
    Maris,
    Thanks for all of that.

    What is that background material made of?
    7 foot wide white cotton sheeting dyed to approximately 18% grey, The dye job wasn't exactly even but I'm not going to redo it. You should have seen the mess involved in trying to boil and mordant more than a hundred square feet of fabric!
    Photography:first utterance. Sir John Herschel, 14 March 1839 at the Royal Society. "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..".

  9. #29
    Maris Rusis's Avatar
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    Re: Harman Direct Positive Images

    Quote Originally Posted by Roger Cole View Post
    Wow, makes me wonder what on earth makes the stuff worth all this?
    Harman Direct Positive Paper offers a rare opportunity to display camera-original material as a final product.

    In aesthetic terms it represents the shortest possible distance between subject and photograph and has a special power and magic because of that. There are philosophical implications about photographic truth, indexicality, absence of manipulation, credibility and trust in the image, and so on. That's going to be the basis of my spiel when (if) I get enough DPP photographs together to mount a gallery scale exhibition.
    Photography:first utterance. Sir John Herschel, 14 March 1839 at the Royal Society. "...Photography or the application of the Chemical rays of light to the purpose of pictorial representation,..".

  10. #30
    bob carnie's Avatar
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    Re: Harman Direct Positive Images

    Ok this photo has me confused, I hope I am not crazy here.

    But Why isn't the shutter open if this is a self portrait into a mirror?


    [QUOTE=Maris Rusis;774485]More on "Old Time Photographer" illustrating the desperate measures invoked to get decent photographs out of Harman Direct Positive Paper.

    There is very little picture generating technology involved in "Old-time Photographer" but there is a lot of sneaky subject management and studio wrangling hidden in the back story.

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