What kind of power and wavelength do I need to use these?
New DCG emulsion supplier.
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Mark Cavin
New DCG emulsion supplier.
Next month. I could send you an empty plastic Slavich container to fill with 4x5s.?!!
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Mark C
New DCG emulsion supplier.
Now talk him into getting a paypal account so we can pay him!!
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Dinesh
New DCG emulsion supplier.
"What kind of power and wavelength do I need to use these?"
DCG has a maximum sensitivity at around 400 or so. It's still pretty sensitive at 532 (these 315 diodes?). I'll put up a sensitivity curve on the site, however these are rough figures:
Lambda(nm) ...............ExposuremJ/sq cm)
488....................................50
514....................................75
532....................................120
There is no "sensitivity" as such for DCG because it's a continuous process of cross linking as opposed to the particulate process in Silver where a specific energy is required to create a speck (I'll also put up a Silver Halide paper to explain these terms). In DCG, the more energy you give it the more it cross links and the harder the Bragg planes and the overall emulsion becomes. The harder the overall emulsion becomes, the more resistant it becomes to swelling and subsequent dehydrating and so the more blue shifted and narrow band it becomes. In other words, the exposure depends a lot on what you want, within certain limits. Hit it with about 20 mJ/sq cm at 488 and you get a sort of orange/yellow, hit it with 50 mJ/sq cm and you'll get green (that's how your skull was made, by the way).
DCG has a maximum sensitivity at around 400 or so. It's still pretty sensitive at 532 (these 315 diodes?). I'll put up a sensitivity curve on the site, however these are rough figures:
Lambda(nm) ...............ExposuremJ/sq cm)
488....................................50
514....................................75
532....................................120
There is no "sensitivity" as such for DCG because it's a continuous process of cross linking as opposed to the particulate process in Silver where a specific energy is required to create a speck (I'll also put up a Silver Halide paper to explain these terms). In DCG, the more energy you give it the more it cross links and the harder the Bragg planes and the overall emulsion becomes. The harder the overall emulsion becomes, the more resistant it becomes to swelling and subsequent dehydrating and so the more blue shifted and narrow band it becomes. In other words, the exposure depends a lot on what you want, within certain limits. Hit it with about 20 mJ/sq cm at 488 and you get a sort of orange/yellow, hit it with 50 mJ/sq cm and you'll get green (that's how your skull was made, by the way).
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Dinesh
New DCG emulsion supplier.
"Next month. I could send you an empty plastic Slavich container..."
This would be great. One problem with DCG is its softness. Unlike Silver, you can't have anything touch the emulsion surface because it scratches so easily.
This would be great. One problem with DCG is its softness. Unlike Silver, you can't have anything touch the emulsion surface because it scratches so easily.
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Tom B.
New DCG emulsion supplier.
Those Slavich boxes are awfully bulky and don't seem to protect plates very well against breakage during shipping. Would a layer of Saran wrap (or similar peelable film) over the gelatin work to protect it enough to allow use of thin cardboard (or foam sheet) spacers between plates resulting a a more compact package?
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JohnFp
New DCG emulsion supplier.
DCG emulsion is pretty soft. Do you remember the packaging days of Agfa 8 x 10's. They had red edge spacers on the two sides of each plate. It kept the plates about 1/4 inch apart and cushioned. The stack was then wrapped in a light tight wrapper then in a cardboard box.
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danny bruza
New DCG emulsion supplier.
http://4c-s.org/v-web/gallery/album09/monaliza2
this is done with dpss green laser 100mw, exposer 5 mins
this is done with dpss green laser 100mw, exposer 5 mins