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Even though I tried to keep accurate tech notes for each exposure years ago (& still do), looking back, my biggest regret was not making a quality comment for each and every exposure in those early years. Without that, i’ve sometimes found old lab notes to be almost useless. Another early mistake was using sticky labels for each hologram when I should have been using a marker that doesn’t fade or fall off over time.

Thanks!

I started with a sequence number in my official paper notebook. I've just started volume 3 so I don't want to change my nomenclature too much... (-:

For DCG, I have condensed the variables into a table at http://www.bobdbob.com/~tjohnson/DCG/ . The images are properly indexed with ISO dates.

First exposure, July 7th? Maybe add 2020 or 20 for your future reference? Nice work & very good to take accurate sequential notes🤪😷...

Nice :)

[img]http://www.bobdbob.com/~tjohnson/DCG/hologram_189.1.jpg[/img]

This is my best one sofar. The picture was taken in my yard in sunlight. It is a bit yellower in real life.

20% 250 bloom gelatin
mold coated with scotch tape shims (2 mils)
dried about 5 days (mostly because I had to go to work...)
sensitized for 1 minute in a 3% solution of K dichromate, rinsed in 1/2 % K dichromate to avoid crystallization.
dried overnight, it was about 12 hours old when exposed.
exposed for 200 seconds, to 100 uW/cm^2 457nm light
So about 14 millijoules/cm^2 (angled at 45 degrees)

washed for 1 minute in distilled water (picked up lots of dichromate)
fixed for 30 seconds in 1 % K metabisulfate, no hardener
swelled in distilled water at 24C for 5 minutes
2 minutes in 70% IPA (24C)
2 minutes in 91% IPA (26C)
2 minutes in 99% IPA (26C)
dried with a heat gun, till too hot to hold

The wash before the fixer seems to make everything much happier.