Search found 795 matches
- Sat Sep 30, 2023 9:03 am
- Forum: General Holography
- Topic: Moving the object to reduce speckle?
- Replies: 9
- Views: 8050
Re: Moving the object to reduce speckle?
It's because dispersion starts at the plate and increases through the depth of the image space. This is why "achromat" or "open aperture" holograms produce an image when you use an H1 with no slit. I always wanted to try "open aperture." I've heard this produces very b...
- Fri Sep 29, 2023 11:55 am
- Forum: General Holography
- Topic: Moving the object to reduce speckle?
- Replies: 9
- Views: 8050
Re: Moving the object to reduce speckle?
BobH and Din, thank you for your replies. Bob, I'm not currently using a mirror except for the dichroics which combine the 3 lasers in the other room. Once the beams go through the hole in the wall, I have a small platform for the spatial filter, which is not attached to the table. The table is a sh...
- Fri Sep 29, 2023 6:23 am
- Forum: General Holography
- Topic: Moving the object to reduce speckle?
- Replies: 9
- Views: 8050
Moving the object to reduce speckle?
This idea was suggested to me by another holographer. Say we have a Denisyuk arrangement with an object/plate/plate holder assembly which is essentially locked together (no movement relative to each other). Now we place this on a small isolation table (which is on air). Nothing else is on the table....
- Thu Sep 28, 2023 1:51 pm
- Forum: holoforum administration
- Topic: Status of email service
- Replies: 3
- Views: 19922
- Sun Sep 10, 2023 9:37 am
- Forum: DCG
- Topic: Angular Bandwidth in DCG
- Replies: 10
- Views: 13484
Re: Angular Bandwidth in DCG
That's fascinating. Thanks for the explanation.
- Sat Sep 09, 2023 2:45 pm
- Forum: DCG
- Topic: Angular Bandwidth in DCG
- Replies: 10
- Views: 13484
Angular Bandwidth in DCG
I was reading a paper which suggested that "angular bandwidth" (which I assume is the number of viewing angles a hologram can be seen from, i.e., narrow angular bandwidth = restricted viewing angles) can be related to spectral bandwidth. The paper suggested that narrow spectral bandwidth i...
- Thu Aug 24, 2023 7:47 am
- Forum: holoforum administration
- Topic: Thank you John Fisher
- Replies: 1
- Views: 6043
Thank you John Fisher
Thank you for maintaining the Holography Forum. It's an invaluable resource!
- Sat Aug 12, 2023 10:06 am
- Forum: General Holography
- Topic: collimated reference beams
- Replies: 5
- Views: 8113
Re: collimated reference beams
Thanks Dave, I'm using a Sapphire 488nm (200mW) right now. The PL 530 is becoming a popular holography laser, it's amazing how much green light is now available to holographers at low cost. By the way, I saw your 275mW green Sapphire head on eBay. I've always wondered to what extent Sapphire control...
Re: Bacteria?
Thanks Din. That's an interesting thought about the hair dryer, I used a new one with a ceramic heating element. Maybe the ceramic was shedding dust. If the problem persists, I'll get out the microscope.
Bacteria?
This morning's DCG has some blank (empty) spots which I haven't seen before. P1010050.JPG On the right side of the image, there is a multitude of tiny <1mm spots which group together at the far right, then spread out more as they go to the left. They're also visible at the bottom. When coating the p...