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Thread: Fumbling towards a correct exposure for Dry Plates

  1. #11
    Drew Bedo's Avatar
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    Re: Fumbling towards a correct exposure for Dry Plates

    A lot of good stuff here. Thanks everyone.

    Now another few questions:

    I understand that the spectral response is deep in the blue end, perhaps even near Ultra Violet. If that is so, is any exposure compensation requirted to account for that? If a scene is metered for ISO 100 film (and I make an exposure on that film) , then adjust for the nominal ISSO 1 speed of the dry plate , as discussed above,. . .is any further adjustment needed for the loss of half the spectrum?

    I assume that best exposures will come at high sun angles (say, 10AM to 3PM), as the "golden hour" just at sun-up and sun-set will be strong in the red end.

    Lenses to be used are "modern" , mid-1990s vintage from Rodenstock, Fuji and Nikon. Can I assume that these are corrected enough to avoid a blue shift in focus (getting really modern "APO" lenses is off the table).
    Last edited by Drew Bedo; 8-Feb-2020 at 05:39.
    Drew Bedo
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    There are only three types of mounting flanges; too big, too small and wrong thread!

  2. #12
    Tin Can's Avatar
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    Re: Fumbling towards a correct exposure for Dry Plates

    Can't really help on that Drew

    I bought about 4 boxes of the glass negs, shot a few and put them away for a while

    Most likely I shoot more this summer, AFTER I see what you do!

    Get in the water, they do work and I think you are covering most of the issues.

    Be very gentle processing them, I use trays
    sin eater

  3. #13
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    Re: Fumbling towards a correct exposure for Dry Plates

    Quote Originally Posted by Drew Bedo View Post
    A lot of good stuff here. Thanks everyone.

    Now another few questions:

    I understand that the spectral response is deep in the blue end, perhaps even near Ultra Violet. If that is so, is any exposure compensation requirted to account for that? If a scene is metered for ISO 100 film (and I make an exposure on that film) , then adjust for the nominal ISSO 1 speed of the dry plate , as discussed above,. . .is any further adjustment needed for the loss of half the spectrum?

    .

    Exposure can vary by a stop depending on cloud cover. Usually it seems to follow visible light close enough that a meter is a help.


    Kent in SD
    Qui sedes ad dexteram Patris,
    miserere nobis.

  4. #14
    Drew Bedo's Avatar
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    Re: Fumbling towards a correct exposure for Dry Plates

    Processing: That's another one.

    I am visually impaired and haven't processed any film since the mid 1990s. Setting up a dark room of any kind in our house is not practical . . .you would have to be here . . . .take my word for it. I have looked at that for years with multiple misses.

    So part of this project will be to find a lab somewhere (anywhere) that will process the exposed plates.

    I am still working on how to handle exposed plates when unloaded from film holders. Post processing storage is yet another issue to be delt with.
    Drew Bedo
    www.quietlightphoto.com
    http://www.artsyhome.com/author/drew-bedo




    There are only three types of mounting flanges; too big, too small and wrong thread!

  5. #15
    Drew Bedo's Avatar
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    Re: Fumbling towards a correct exposure for Dry Plates

    Quote Originally Posted by Two23 View Post
    Exposure can vary by a stop depending on cloud cover. Usually it seems to follow visible light close enough that a meter is a help.


    Kent in SD

    A help? Good to know!

    I intend to shoot duplicates of a scene with the dry plates and T-Max 100, so we will see how much "help" a meter is.
    Drew Bedo
    www.quietlightphoto.com
    http://www.artsyhome.com/author/drew-bedo




    There are only three types of mounting flanges; too big, too small and wrong thread!

  6. #16
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    Re: Fumbling towards a correct exposure for Dry Plates

    Quote Originally Posted by Drew Bedo View Post

    1.Setting up a dark room of any kind in our house is not practical.

    2. So part of this project will be to find a lab somewhere (anywhere) that will process the exposed plates.

    3. I am still working on how to handle exposed plates when unloaded from film holders.

    1. They can be processed in a Stearman SP-445 with special available holder or in the SP-810 that doesn't need a holder. Two at a time in SP-445, four at a time in the SP-810. Load them in an interior bathroom or even closet at night. You can use red safe light with these. I originally process them in trays in my bathtub, using red light. Interior bathroom no windows and lights off in adjoining room.

    2. Blue Moon in Portland does them.

    3. In dark closet or interior bathroom at night with lights off in adjoining room, load them into 4x5 box. Put a piece of the glassine paper that comes with the plates between each and also the top one so they don't scratch the emulsion.


    Kent in SD
    Qui sedes ad dexteram Patris,
    miserere nobis.

  7. #17

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    Re: Fumbling towards a correct exposure for Dry Plates

    AS it says on the front of the box, the plates are orthochromatic. In other words, they are most sensitive to blue light and basically insensitive to red. In the middle of the day , from about 2 hours after sunrise to about 2 hours prior to sunset, expose as you do with panchromatic film using your regular meter. early and late in the day there is more red in the spectrum , thus less blue. Increase the exposure at least a stop in these cases. I have used so much Ortho filmin my life I can Pretty well judge the necessary adjustment. I began photography when most film was orthochromatic. A CD can act as a prism to show you approximately the %age of red in the spectrum. Simply bounce the light off it and look at the bands of color.
    The instruction in the box concerning development are excellent. Follow them and don't vary until you get experienced with the product, at least 2 or 3 boxes. This is exactly the direction I give to my students who want to try the plates.

  8. #18
    Drew Bedo's Avatar
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    Re: Fumbling towards a correct exposure for Dry Plates

    Jim: Thanks for that. Great info. and concise . . .without speculation; great. Glad to hear that time available for shooting is a bit extended beyond my gues. Thanks too for the experiential tip on extending exposures into the later afternoon.
    The CD tip is new to me. I will give it a go. I will be using a changing tent for handling film and plates.

    Processing; Yeah. Our house has one interior room. It is a small closet stuffed with hanging clothes. I have been told that it is off limits for wet chemistry or anything else photographic. Same goes for our one bathtub and the room it lives in.

    Two23: Blue Moon it is then . . . . for as long as the money holds out!
    Drew Bedo
    www.quietlightphoto.com
    http://www.artsyhome.com/author/drew-bedo




    There are only three types of mounting flanges; too big, too small and wrong thread!

  9. #19
    Tin Can's Avatar
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    Re: Fumbling towards a correct exposure for Dry Plates

    The plates I have, have thin paper interleaving, be sure to save this for use again for outbound shipping to Blue Moon to avoid scratches.

    I also think you could find an opaque container or a used SP-445 (they out of stock at Steerman) to be used in your dark tent

    I say this because you already plan to load holders in a tent and a SP-445 of other DIY thing could be made and do one plate at a time, in the same tent

    I realize the closet is out of bounds! For very good reasons

    I do only one plate at a time in a 3 5X7 trays. Using the water stop tray twice, the second time for washing, very gently

    I have a dedicated small plastic spatula, I use for for putting the plates in and out of the trays under red safe light

    I have read in the distant past before electricity everywhere, windows were temporarily covered with rubylith for wet plate and maybe more


    Also all wet plate users make a portable tiny darkroom


    https://www.largeformatphotography.i...l=1#post980254
    sin eater

  10. #20

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    Re: Fumbling towards a correct exposure for Dry Plates

    Quote Originally Posted by Tin Can View Post
    The plates I have, have thin paper interleaving, be sure to save this for use again for outbound shipping to Blue Moon to avoid scratches.

    I also think you could find an opaque container or a used SP-445 (they out of stock at Steerman) to be used in your dark tent

    I say this because you already plan to load holders in a tent and a SP-445 of other DIY thing could be made and do one plate at a time, in the same tent

    I realize the closet is out of bounds! For very good reasons

    I do only one plate at a time in a 3 5X7 trays. Using the water stop tray twice, the second time for washing, very gently

    I have a dedicated small plastic spatula, I use for for putting the plates in and out of the trays under red safe light

    I have read in the distant past before electricity everywhere, windows were temporarily covered with rubylith for wet plate and maybe more


    Also all wet plate users make a portable tiny darkroom


    https://www.largeformatphotography.i...l=1#post980254
    Only the SP-445 rev 3 is out. Rev 4 is available.

    https://shop.stearmanpress.com/colle...cessing-system

    (No affiliation)

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