Search found 20 matches

by jeff-blyth
Thu May 09, 2019 4:54 pm
Forum: Beginning Holography
Topic: Homemade Plates
Replies: 19
Views: 20764

Re: Homemade Plates

Yes OK then, I will try to help when you have made some more plates and have more data . The plates should keep for many months if you don't treat them with the sensitizer or TEA soln. until you want to use them Although the bath containers are you say “stainless steel” , can you float one on top of...
by jeff-blyth
Tue Jul 17, 2018 7:25 pm
Forum: General Holography
Topic: D.I.Y. holographic photopolymer
Replies: 26
Views: 22926

Re: D.I.Y. holographic photopolymer

Hi Martin, It has been known for a long time that you can only make transmission fringes i.e. perpendicular to the substrate when you start with a liquid that will then gel under laserlight. Those perpendicular fringes are then spatially anchored to the glass substrate like the teeth on a comb and t...
by jeff-blyth
Wed Jan 03, 2018 4:30 pm
Forum: DCG
Topic: Dehydrating with methanol instead of IPA?
Replies: 6
Views: 11936

Re: Dehydrating with methanol instead of IPA?

[quote][/quote] I think you are working with a paradigm which is quite faulty there. The ipa only penetrates where there is water and not where there is gelatin. Gelatin and ipa (and acetone) are not compatible but gelatin and methanol are very slightly compatible. It is not the desiccation that is ...
by jeff-blyth
Thu Dec 21, 2017 5:41 pm
Forum: DCG
Topic: Dehydrating with methanol instead of IPA?
Replies: 6
Views: 11936

Re: Dehydrating with methanol instead of IPA?

I did try this once and concluded that it did not work nearly as well as ipa. The problem being I think, that gelatin has a slight tolerance to absorbing methanol, therefore methanol cannot rip the water out of gelatin as well as ipa can. However that really only applies to the final bath. I bet you...
by jeff-blyth
Wed Dec 20, 2017 9:24 pm
Forum: Beginning Holography
Topic: Single Beam Splitting for enhanced Denisyuk reflections
Replies: 1
Views: 5140

Single Beam Splitting for enhanced Denisyuk reflections

Beam splitting and “single beam” holography “Single beam” holography commonly known as Denisyuk or reflection holography is really a misnomer because of course all holography involves the interaction of never less than 2 beams from a single source. This means that we always have to split the beam up...
by jeff-blyth
Sat Dec 09, 2017 2:42 pm
Forum: DCG
Topic: Red sensitivity of MBDCG
Replies: 8
Views: 11587

Re: Red sensitivity of MBDCG

Well thank you for that Dinesh, you have given me the bit of insight that when it comes to forming holographic fringes in a Denisyuk reflection holo.--- I have now grasped that the process is independent of collimation! However I do have a big problem understanding your statements about intensity ef...
by jeff-blyth
Sat Dec 09, 2017 7:52 am
Forum: DCG
Topic: Red sensitivity of MBDCG
Replies: 8
Views: 11587

Re: Red sensitivity of MBDCG

Dinesh, I know of all people your calcs for DCG comes from years of experience and it is good that you are helping Pluto get it sorted. But I just want to play a bit of Devil's advocating here. In theory collimated returning light from a mirror as object can result in the bright fringes receiving al...
by jeff-blyth
Tue Aug 01, 2017 9:48 am
Forum: Beginning Holography
Topic: Homemade Plates
Replies: 19
Views: 20764

Re: Homemade Plates

I have had to do an update on the quality of silver nitrate purchased . It turns out that there is one really bad impurity that has to be as low as possible, and that is silver chloride (AgCl), otherwise you get bad grain growth and scatter. I have updated the recipe procedure to try to deal with th...
by jeff-blyth
Thu Jul 27, 2017 3:35 am
Forum: Beginning Holography
Topic: Homemade Plates
Replies: 19
Views: 20764

Re: Homemade Plates

Hi Heferkimbo,
How did it go with your last tests? Please let me know. My username is jeffinbath for my email @ ntlworld.com. It is helpful to me to know what can occur when someone uses my system with some chemicals bought locally on the otherside of the world.
by jeff-blyth
Tue Jul 11, 2017 7:17 pm
Forum: AgX
Topic: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?
Replies: 34
Views: 52286

Re: Which chemistry for "HOLOFILM 250 PAR" from Applied Holographics PLC ?

Hi Thycore, From what you say about seeing interference (colours )but no red image, ---this indicates I think that you have smudged your reflection fringes due to a tiny movement perpendicular to the plane of the film. Such movements do not do much damage to spurious transmission gratings whose frin...