Search found 794 matches
- Mon Jan 22, 2024 9:47 am
- Forum: For Sale / Want to Buy / Trade
- Topic: Donate and Help Conservation Research?
- Replies: 14
- Views: 3853
Re: Donate and Help Conservation Research?
Hi, I think this would be a very interesting area of research. As far as I know, there has never been an independent and unbiased evaluation of the permanence or longevity of holograms. Holograms vary enormously in terms of recording material, processing regime, sealing or mounting technique, and ty...
- Fri Jan 19, 2024 10:03 am
- Forum: General Holography
- Topic: Moving the object to reduce speckle?
- Replies: 9
- Views: 7583
Re: Moving the object to reduce speckle?
Thanks for the clarification, that's interesting. I don't know why that would cause a dimmer hologram.
- Fri Jan 19, 2024 6:49 am
- Forum: General Holography
- Topic: Moving the object to reduce speckle?
- Replies: 9
- Views: 7583
Re: Moving the object to reduce speckle?
Thanks for sharing your results. I was wondering if you quantified the actual distance the end of your fiber was moving/vibrating during exposure. Maybe it resulted in too much of a loss in spatial coherence? It's difficult to get a handle on such small distances, so I recently bought an inexpensive...
- Thu Nov 02, 2023 2:59 pm
- Forum: Off Topic
- Topic: Whatever Became of Holography?
- Replies: 19
- Views: 36922
Re: Whatever Became of Holography?
OK, thanks
- Wed Nov 01, 2023 2:51 pm
- Forum: Off Topic
- Topic: Whatever Became of Holography?
- Replies: 19
- Views: 36922
Re: Whatever Became of Holography?
Unfortunately a sub-group of display holographers has swallowed the idea of picture meaning an actual picture of a cat, for example, and get pretty nasty when the idea of 'picture' in the scientific sense of information is broought forward. I don't know if you're referring to me or not, Din, but I'...
- Tue Oct 31, 2023 9:17 am
- Forum: Off Topic
- Topic: Whatever Became of Holography?
- Replies: 19
- Views: 36922
Re: Whatever Became of Holography?
In terms of display holography, a person who is, first and foremost, a "holographer" may be a thing of the past. Display holograms had something of a mainstream presence in the 1980's and into the first half of the 1990's. Unfortunately, holograms were presented to the public as a novelty....
- Tue Oct 31, 2023 5:50 am
- Forum: DCG
- Topic: Angular Bandwidth in DCG
- Replies: 10
- Views: 12670
Re: Angular Bandwidth in DCG
Thank you for the insights, Din, I appreciate it.
- Sun Oct 29, 2023 8:29 am
- Forum: DCG
- Topic: Angular Bandwidth in DCG
- Replies: 10
- Views: 12670
Re: Angular Bandwidth in DCG
I've attached two pages from a 1979 Applied Optics paper by Chang and Leonard: "Dichromated gelatin for the fabrication of holographic optical elements". With regards to angular bandwidth, I found it interesting that they reported such large variances with regards to dichromate concentrati...
- Fri Oct 27, 2023 6:17 am
- Forum: Gallery
- Topic: recent DCG hologram
- Replies: 4
- Views: 19199
- Wed Oct 25, 2023 12:40 pm
- Forum: Gallery
- Topic: recent DCG hologram
- Replies: 4
- Views: 19199
Re: recent DCG hologram
Thank you Jody and Din. This is another one done this morning: P1010034.JPG It's not as bright as the other one, probably because I was trying for a more narrowband result. I used more green laser light, and the colors improved somewhat. While in the 20C 91%, the colors looked quite good, but after ...