Let there be green

After several days of tests I’ve gotten a couple of decent transmission holograms on VRP-M using a Coherent 315m.

GreenShot1


This
first shot shows some objects which are 9" from the plate, sitting on
the table. R2, Snoopy and Barad-dur models. Click on the image to see a
larger version.

The
second shot shows an owl statue (20" from the plate), part of my
collimating mount, the top of Barad-dur and a mirror which is
reflecting an image of R2 and Snoopy which virtual image is 38" from
the plate.

The
final shot is angled up some to show a reflection of the owl that was
coming off the plate holder glass, for a total travel of 60". The owl
reflection is just below and to the left of the bright spot at the top
of the picture.

Unfortunately it turns out that the 8×10"
package of film I’ve been using is nearly toast. I’m guessing that the
exceptional humidity we had this spring and early summer got to it and
that’s what’s causing the high fog levels I’m seeing after development.

I
came to this conclusion after receiving a new package of 4×5" from
Integraf and putting it in the same setup as show above. The image came
out just as bright (except where I ended up with some movement *sigh*)
and there was no fogginess of the film after removing it from the
bleach. While somewhat noisy, that hologram wasn’t nearly as noisy as
prior tests.

I did find though that putting the foggy film
through a post treatment of 2% ascorbic acid greatly increases
contrast, just as it did with PFG-01 and removes the fog problem. So I
can make use of the ruined film but I’ll have to treat all the
resulting holograms with ascorbic which I did somewhat rarely with
PFG-01.

The hologram was exposed for 22 seconds, developed for 20 seconds in JD2, bleached in EDTA and post-treated with 2% ascorbic acid.

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Author: Michael Harrison

Husband, Programmer, Irish dancer, tinkerer, astronomer, layabout (as much as possible)

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