New DCG emulsion supplier.

These are all of the old posts from the first two years of the forum. They are locked.
Updated: 2005-03-28 by HoloM (the god)
Larry

New DCG emulsion supplier.

Post by Larry »

What kind of power and wavelength do I need to use these?

Mark Cavin

New DCG emulsion supplier.

Post by Mark Cavin »

Next month. I could send you an empty plastic Slavich container to fill with 4x5s.?!!
JohnFP

New DCG emulsion supplier.

Post by JohnFP »

Ok, so where it the "DCG Plates" button on your web page?

Mark C

New DCG emulsion supplier.

Post by Mark C »

Now talk him into getting a paypal account so we can pay him!!
Dinesh

New DCG emulsion supplier.

Post by Dinesh »

"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).
Dinesh

New DCG emulsion supplier.

Post by Dinesh »

"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.
danny bruza

New DCG emulsion supplier.

Post by danny bruza »

contact me. ive use his plates with dpss green....
Tom B.

New DCG emulsion supplier.

Post by Tom B. »

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?
JohnFp

New DCG emulsion supplier.

Post by JohnFp »

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.
danny bruza

New DCG emulsion supplier.

Post by danny bruza »

http://4c-s.org/v-web/gallery/album09/monaliza2
this is done with dpss green laser 100mw, exposer 5 mins
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