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Chinese figurines and random stuff

Posted: Tue Aug 07, 2018 6:12 pm
by pluto
Haven't posted here in a while!

One of my better and more recent holograms:

Pic:
Image

Video:
https://www.youtube.com/watch?v=1cIGXvEQpUc

Some more:

- Experimenting with depth: https://www.youtube.com/watch?v=7dqZ5bj5tvg

- Kind of a nice figurine (overexposed in the middle? underexposed? hmm) https://www.youtube.com/watch?v=n7EuEWkOs4A

488nm / ~175mW

I capture a video of each hologram that I make, so check out my channel if you want to see a bunch of really bad holograms :P

Re: Chinese figurines and random stuff

Posted: Mon Aug 13, 2018 5:16 pm
by Steven
Nice job pluto.
Narrowband and low noise.

Re: Chinese figurines and random stuff

Posted: Wed Aug 15, 2018 8:32 pm
by ahgu
Pluto, It looks amazing.
What gelatin do you use? What do you do to get it so sharp ? Can you post your procedure?

Re: Chinese figurines and random stuff

Posted: Thu Aug 16, 2018 12:37 am
by pluto
I think you contacted me by private message, but here's my response for posterity:
I use Knox gelatin. Let me just list some things about my setup.

I use a 488nm 200mW laser, often exposing at 150mW or so. My DCG formula is 200-21-1.5 (water-gelatin-potassium dichromate)
And some answers to emailed questions if anybody is curious:
Are you using the supermarket knox?
Yes
I am using AmDi, Why do you use KDi? What do you think of NaDi?
It's just what I ordered initially. AmDi is supposedly a bit more sensitive -- I may order some soon. NaDi is meant to be better than KDi as well, more soluble I think?
I am doing the dip method. Mold coating, Dip in 3% Amdi solution for 1min.
I do veil coating. I heat up the glass plate with a heat gun to ~40C, then coat the glass plate. I rotate the plate a little bit, but I don't spin. Very lazy technique -- probably the cause of most of the imperfections in my holograms.
What is the develop steps? Fixer, IPA concentration and time? I do 68%, 99% 100% all in ambient temp
I don't use fixer -- perhaps I should. I experiment with temperatures and concentrations, but typically I do:

1) Water wash for 60-90 seconds (~20c)

2) 70% IPA bath for with gentle agitation for 60 seconds (~20c)

3) 99% IPA bath with gentle agitation for 60-90 seconds (~20c, sometimes up to 30c)

I dry with a heat gun. Depending on how the hologram turns out after drying with moderate heat, sometimes I turn it to the hottest setting and heat it up very hot. This has produced brighter results at times, but also more noise.
Haze in the middle, when you view the hologram in a large angle, you see whitish haze, not crystal clear.
I believe this is because of internal reflections in the glass. I don't mask off the edges, so at the steep angle you see the reflection from the laser hitting the side of the glass.

I take a quite a lazy approach to holography... doing everything extremely carefully sometimes makes making holograms a bit tedious and takes the fun away. The way I see it, I'm experimenting with different parameters, and once I feel I understand how they affect the final result, then I will take the time to try to make a really nice hologram.

Re: Chinese figurines and random stuff

Posted: Sun Sep 30, 2018 6:06 am
by Grayham
Hi,

The hologram looks nice and crisp.
May I ask what light you are using to reconstruct the hologram.

Thank you
Grayham