Ronald Reagan .....his will be deeply missed

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)
Dinesh

Ronald Reagan .....his will be deeply missed

Post by Dinesh »

I have it straight from the horses mouth (No, not Reagan, another 'horse') that Reagan himself did not like the portrait because of the black eyes. He felt it was too spooky. The reason is that back in the days of ruby lasers they could not catch that kind of detail.
JohnFP

Ronald Reagan .....his will be deeply missed

Post by JohnFP »

Hey Dinesh, the color looks pretty close to 514. I would love to have that and try a contact copy in DCG, no?
Dinesh

Ronald Reagan .....his will be deeply missed

Post by Dinesh »

The problem is that it's a little weak for copying onto DCG. To copy onto DCG, the master needs to be pretty bright otherwise it's difficult getting a good ratio. If you do it single beam and the master is poor, the ratio is too weak.

This aso has a bearing on the discussion between you and Danny about exposure at 535 with the 315. At PCGG1 we used plates that you brought along that I believe was fresh while Danny used plates that I made up about two weeks earlier. Also, the image at PCGG1 was a single beam divergent directly from the laserwith one mirror. While I believe Danny's "Mona Lisa" was from an H1. These factors may be responsible for the difference in exposures. As I said, there's no real "sensitivity" of DCG since it's a continuous process. The longer you zap it the greener it gets and/or brighter or dimmer and/or more or less narrow band. I've shot the same DCG at 40 odd mJ/sq cm for display and 400 mJ/sq cm for a HOE! Also, comparing sensitivities for two different DCG emulsions made with different gelatins of different bloom strengths and different ratios of DC to G is comparing apples to oranges. Even the same bloom strength from different manufacturers will behave differently. In the end, a 2 minute exposure of a single beam shot direct from the laser may well be equal to a 5 min H1-H2 shot.
I intend to post my exposure and development in detail over the weekend.
JohnFP

Ronald Reagan .....his will be deeply missed

Post by JohnFP »

Yup good points. Two weeks old huh? The ones we used at PCG were 48 hours old. And another fantastic point which elluded me, a contact copy from another hologram. Yup, got it now. I can see the large varriances.

The point I was trying to drive home is that a 4 x 5 single beam reflection can be shot at a much shorter time. I just didn't want potential DCGers to be dicouraged from trying.

Man, I enjoy your post sooooo much. Although I have to be in a certain mind set to actually try to follow your formulas. What was the cereal you eat? I have to switch.

Peace friend!
JohnFP

Ronald Reagan .....his will be deeply missed

Post by JohnFP »

with older plates which have become somewhat hardened and a weak object beam, I think he got a great hologram. So to take the DCG to the crack point what do you think? I say, use fixer with less hardener or even no hardener such that the emulsion can expand more in the water bath after the fixer. And I would increase the temperature of the water bath after the fixer and ultimately increase the temperatures of the first three alcohol baths to match the temperature of that water bath. Then increase the temperature of the final bath by 10 - 15 % over the the the other alcohol baths. In addition, I would place the contact copy with the emulsion away from the object hologram to allow the "light hardening (exposure)" to harden closer to surface more thus creating a more differential in hardening from surface to depth and with the above processing, creating a more differenial swelling and ultimately a wider replay bandwith (brighter).

What do you think?
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