RGB tests with HX200 photopolymer

Holography related topics.
Loic74
Posts: 39
Joined: Sat Aug 10, 2019 9:09 pm
Location: France

RGB tests with HX200 photopolymer

Post by Loic74 » Sun Oct 04, 2020 3:21 pm

Denisyuk setup, three wavelengths (640, 532, 457), 3mins exposure or so.
Proper lamination on glass is difficult. Tips welcome :)

https://youtu.be/SzVLz2yhPO4
https://youtu.be/pP2MUUNUlaE

holomaker
Posts: 761
Joined: Wed Jan 07, 2015 8:01 am

Re: RGB tests with HX200 photopolymer

Post by holomaker » Mon Oct 05, 2020 7:30 am

Super nice ! What thickness glass are you using to carry the PP, I found thicker works better, like 1/4”...

Loic74
Posts: 39
Joined: Sat Aug 10, 2019 9:09 pm
Location: France

Re: RGB tests with HX200 photopolymer

Post by Loic74 » Mon Oct 05, 2020 10:47 am

Thanks.
I have used 2 and 3mm 4x5" plates (recycled from Agfa and Ultimate Agx).
1/4" sounds very thick, I wonder what makes it work better with thicker plates

holomaker
Posts: 761
Joined: Wed Jan 07, 2015 8:01 am

Re: RGB tests with HX200 photopolymer

Post by holomaker » Mon Oct 05, 2020 11:29 am

It’s what they recommend on PP?

Loic74
Posts: 39
Joined: Sat Aug 10, 2019 9:09 pm
Location: France

Re: RGB tests with HX200 photopolymer

Post by Loic74 » Mon Oct 05, 2020 11:47 am

holomaker wrote:
Mon Oct 05, 2020 11:29 am
It’s what they recommend on PP?
No idea.
Here they laminate on 1mm glass: http://geola.com/product/photopolymer/

Sergio
Posts: 100
Joined: Tue Jan 20, 2015 12:25 pm

Re: RGB tests with HX200 photopolymer

Post by Sergio » Tue Oct 13, 2020 5:45 pm

Kodak used 4 x 5 in plates at 1mm THK.
Agfa used more, 2mm, perhaps

BobH
Posts: 403
Joined: Tue Jan 06, 2015 10:26 pm
Location: Mesa, AZ

Re: RGB tests with HX200 photopolymer

Post by BobH » Tue Oct 13, 2020 10:16 pm

Agfa was 1.5mm for 4x5", 3mm for larger. 1mm is fine for photopolymer, even 0.7mm. Thicker works better for DCG because DCG is formed via crosslinking, which can bend substrates that are too thin during exposure causing motion fringes.

Din
Posts: 259
Joined: Thu Mar 12, 2015 4:47 pm

Re: RGB tests with HX200 photopolymer

Post by Din » Wed Oct 14, 2020 8:35 am

BobH wrote:
Tue Oct 13, 2020 10:16 pm
Agfa was 1.5mm for 4x5", 3mm for larger. 1mm is fine for photopolymer, even 0.7mm. Thicker works better for DCG because DCG is formed via crosslinking, which can bend substrates that are too thin during exposure causing motion fringes.
You can use very thin glass for dcg holograms. Don Broadbent coated on glass less than 1mm thick, and so have we. The problem occurs in coating. We use Meyer bars to coat, which means pressure on the glass as you coat, which can crack the glass. You have to coat very delicately. You can coat thin films by some sort of 'flow' method, but it's difficult to accurately determine emulsion thickness and uniformity. Emulsion thickness and uniformity is not so important for display holography because in display holography, brightness is more important than efficiency and the variability in photopic response is broad. However, in technical holography, the thickness has to be known quite precisely. We measured our emulsion thickness to 10%.

stefanosica
Posts: 7
Joined: Mon Apr 03, 2017 10:09 am

Re: RGB tests with HX200 photopolymer

Post by stefanosica » Wed Oct 14, 2020 1:34 pm

BobH wrote:
Tue Oct 13, 2020 10:16 pm
Agfa was 1.5mm for 4x5", 3mm for larger. 1mm is fine for photopolymer, even 0.7mm. Thicker works better for DCG because DCG is formed via crosslinking, which can bend substrates that are too thin during exposure causing motion fringes.
Bob, based on your great experience, what is the best procedure to temporarily mount the photopolymer on the glass support without trapping air bubbles which, due to the micro-movements induced during exposure, will inevitably result in black spots on the final hologram ? Thank you

BobH
Posts: 403
Joined: Tue Jan 06, 2015 10:26 pm
Location: Mesa, AZ

Re: RGB tests with HX200 photopolymer

Post by BobH » Thu Oct 15, 2020 8:52 am

First, I do it in a dedicaterd area that's kept clean. I use an anti-static airgun (pictured below) to blow the dust off the glass plate first. That keeps dust from being attracted to the surface. Then I use a small laminator I got and modified 20+ years ago to put the film down. Finally, I trim with a razor blade to prevent the edges from lifting while handling the plate. No bubbles.

https://www.terrauniversal.com/blog/ion ... t-quality/

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