Search found 440 matches

by BobH
Tue Dec 07, 2021 10:50 am
Forum: holoforum administration
Topic: Insults and character assassination
Replies: 16
Views: 9333

Re: Insults and character assassination

If a question has been asked, the question must be answered, not deflected by insults. "(not the polarisation, which is a vector, as R. Rallison has published, and some holographers believe so fervently that they attempt to silence genuine criticism based on the literature of the subject , lik...
by BobH
Mon Dec 06, 2021 10:21 am
Forum: The Dump
Topic: emulsion thickness
Replies: 4
Views: 3843

Re: emulsion thickness

Those who comment on engineering matters who then expect to be "believed" as a matter of faith, don't have a lot of credibility with scientists and engineers. I suppose that's why I am currently busy working on multiple HOE projects with multiple clients, and you're sitting at home trolli...
by BobH
Sun Dec 05, 2021 1:21 pm
Forum: AgX
Topic: emulsion thickness
Replies: 17
Views: 11424

Re: emulsion thickness

I expect Mr. Pratheep can ask for clarification himself, if necessary after reading the linked information in my response. I used an Ocean Optics USB2000 spectrometer at Digilens for the measurement, and still do today.
by BobH
Sun Dec 05, 2021 9:28 am
Forum: AgX
Topic: emulsion thickness
Replies: 17
Views: 11424

Re: emulsion thickness

I'd remove some of the emulsion, clamp another plate of glass to the emulsion surface, and use the spectrometer to measure the air gap over the area removed. This method assumes an rms of zero, which it cannot be. Regardless, it will work fine as I used the technique for many years while at Digilens.
by BobH
Sat Dec 04, 2021 4:33 pm
Forum: AgX
Topic: emulsion thickness
Replies: 17
Views: 11424

Re: emulsion thickness

I'd remove some of the emulsion, clamp another plate of glass to the emulsion surface, and use the spectrometer to measure the air gap over the area removed.
by BobH
Sat Dec 04, 2021 10:06 am
Forum: AgX
Topic: emulsion thickness
Replies: 17
Views: 11424

Re: emulsion thickness

by BobH
Fri Jul 30, 2021 9:05 am
Forum: General Holography
Topic: Bayfol
Replies: 20
Views: 9789

Re: Bayfol

I use large microscope slides from Ted Pella for cover glass, and Norland NOA107 UV cured adhesive for capping photopolymer holograms.
by BobH
Tue Mar 02, 2021 10:03 am
Forum: Beginning Holography
Topic: Hello and I have a transport not sure if it’s Motion or 70mm. Still
Replies: 1
Views: 4836

Re: Hello and I have a transport not sure if it’s Motion or 70mm. Still

It's a vintage film transport from the 1970s used to make holograms in an industrial environment. Quite obsolete. Film for it not made in decades. I'd be interested if you ever want to sell it, for display with similar old holography and laser equipment. There are much easier and cheaper ways to do ...
by BobH
Tue Feb 09, 2021 10:07 am
Forum: General Holography
Topic: Nick Brandreth’s Lippmann Plates
Replies: 2
Views: 2424

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: 2464

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 2452 times