Search found 402 matches

by BobH
Tue Feb 09, 2021 10:07 am
Forum: General Holography
Topic: Nick Brandreth’s Lippmann Plates
Replies: 2
Views: 81

Re: Nick Brandreth’s Lippmann Plates

I notice in these videos that the round viewing aperture is also recorded into the image. I wonder if that means that the Lippmann photograph recorded the three dimensional position of the lens used to focus the image onto the plate?
by BobH
Tue Jan 19, 2021 10:07 am
Forum: General Holography
Topic: Mounting Photopolymer Film
Replies: 3
Views: 140

Re: Mounting Photopolymer Film

Here's a sample, on 50x75mm glass. It's a recent HOE, with a palindrome number.
Palindrome Hologram.jpg
Palindrome Hologram.jpg (423.15 KiB) Viewed 128 times
by BobH
Tue Jan 19, 2021 9:52 am
Forum: General Holography
Topic: Mounting Photopolymer Film
Replies: 3
Views: 140

Mounting Photopolymer Film

An easy way to mount photopolymer film to glass plates is to use a pouch laminator. The one I've used since the mid-1990s is the Ibico GL-9, often still available on Ebay. They were made first in Mexico, then in Korea. Be certain to get one made in Korea (it is mentioned on the label on the bottom),...
by BobH
Sun Nov 08, 2020 9:13 pm
Forum: Beginning Holography
Topic: Holographic Optical Element (HOE) of simple reflection mirror
Replies: 13
Views: 1279

Re: Holographic Optical Element (HOE) of simple reflection mirror

System #2 if you don't have a stable table. System #1 if you do, and want best results. Both will work fine. Others may say system #2 gives best results.
by BobH
Wed Oct 21, 2020 9:18 pm
Forum: Optics
Topic: Question About Cylindrical Holograms.
Replies: 2
Views: 1388

Re: Question About Cylindrical Holograms.

You have it essentially right, but in practice a computer generated image would be used (instead of a sculpture), and that image would be digitally predistorted to give you what you want. There would also be a huge problem with lighting the resulting film, unless the reference beam used to make the ...
by BobH
Mon Oct 19, 2020 8:20 am
Forum: Beginning Holography
Topic: Horizontal stripes - along same depth, like ISO lines...
Replies: 17
Views: 1116

Re: Horizontal stripes - along same depth, like ISO lines...

My favorite tape too, and a "must have" for any hololab. You're right about edge "ringing" from cards used to mask edges, but if they are only a few inches away, the issue is minimized. Also, I'd worry about tape touching photopolymer that's only very lightly attached to the glass. If one uses ink o...
by BobH
Sun Oct 18, 2020 2:40 pm
Forum: Beginning Holography
Topic: Horizontal stripes - along same depth, like ISO lines...
Replies: 17
Views: 1116

Re: Horizontal stripes - along same depth, like ISO lines...

Those lines can form from reflections off the bottom edge too. I like to use cardboard masks to block light from hitting the edges. Nothing to clean. Really nice to see such good results with that material after four years! Especially with a darkish subject. I think the "iso lines" you mentioned at ...
by BobH
Sun Oct 18, 2020 8:58 am
Forum: General Holography
Topic: RGB tests with HX200 photopolymer
Replies: 17
Views: 1382

Re: RGB tests with HX200 photopolymer

The one I use does not have an LED light on the nose.
by BobH
Thu Oct 15, 2020 10:38 am
Forum: General Holography
Topic: RGB tests with HX200 photopolymer
Replies: 17
Views: 1382

Re: RGB tests with HX200 photopolymer

Tank of nitrogen.
by BobH
Thu Oct 15, 2020 8:52 am
Forum: General Holography
Topic: RGB tests with HX200 photopolymer
Replies: 17
Views: 1382

Re: RGB tests with HX200 photopolymer

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 wit...