Search found 403 matches
- Thu Oct 12, 2023 8:53 am
- Forum: DCG
- Topic: Angular Bandwidth in DCG
- Replies: 10
- Views: 14698
Re: Angular Bandwidth in DCG
Remember also, if there's water in the film, you have to fix for longer to draw out the water. Don Broadbent and his student Augie Muth both had humidifiers in the coating room to control the water content that seeped into the film during the drying phase. If you don't draw out the excess humidity,...
- Mon Oct 09, 2023 12:24 pm
- Forum: DCG
- Topic: Angular Bandwidth in DCG
- Replies: 10
- Views: 14698
Re: Angular Bandwidth in DCG
Dave, yes, all of the things you mention will affect spectral response. Thickness: The thicker the emulsion, the more the differential swelling, because, as I said before, the top layers of the emulsion continue swelling as the water penetrates deeper into the emulsion. This means that for a thick e...
- Tue Oct 03, 2023 12:54 pm
- Forum: General Holography
- Topic: Open aperture holograms w/lens
- Replies: 2
- Views: 15764
Re: Open aperture holograms w/lens
One of the problems that plagues display holography is the plethora of names for specific types of holograms. This is the case here, where "open aperture holograms" in Saxby is not "open aperture holograms" in the Handbook. The phrase "open aperture hologram" or "a...
- Fri Sep 29, 2023 2:08 pm
- Forum: General Holography
- Topic: Moving the object to reduce speckle?
- Replies: 9
- Views: 8789
Re: Moving the object to reduce speckle?
I did try placing my finger on the isolation table while making an exposure. (I may be completely mistaken, but you or someone else mentioned something like this -- sorry if I have you confused with another holographer.) The motion I introduced was probably huge -- maybe a few millimeters. (Another...
- Fri Sep 29, 2023 10:41 am
- Forum: General Holography
- Topic: Moving the object to reduce speckle?
- Replies: 9
- Views: 8789
Re: Moving the object to reduce speckle?
Yes, no and possibly irrelevant. Speckle is caused by the rms of a surface, a figure giving the non-uniformity of an apparently flat surface. So, if you have two nearby points on a surface where the variation in height is > λ/2 (~ 300nm), then you get interference due to the extreme coherence of the...
- Thu Sep 28, 2023 1:38 pm
- Forum: Off Topic
- Topic: Mixed Reality
- Replies: 2
- Views: 7044
Re: Mixed Reality
Hi Jody It's from today's (9/28) New York Times Business/Technology Section. It's too large for me to scan all of it, but here ( https://www.nytimes.com/2023/09/27/technology/personaltech/meta-quest-3-vr-headset.html ) the full article. You'll need a Times subscription to read all of it. Basically, ...
- Thu Sep 28, 2023 11:50 am
- Forum: Off Topic
- Topic: Mixed Reality
- Replies: 2
- Views: 7044
Mixed Reality
From the article: "Imagine reading a holographic recipe in the corner of your eye, while cooking." Also: "After a two hour session playing with Quest 3, I removed the goggles and asked Meta employees the $10 billion question (that's the amount the company invests annually in VR techno...
- Thu Sep 28, 2023 8:38 am
- Forum: holoforum administration
- Topic: Status of email service
- Replies: 3
- Views: 21522
Re: Status of email service
Still, I get some gems that arrive in my inbox. Here is one from today I felt compelled to share. I particularly like the "I think you have a 7+ figure business" part. I had no idea we were so valuable. The heck with 7 figures! We're over 9 figures! Somewhere between 3 and 10 billion - ht...
- Tue Sep 12, 2023 8:47 am
- Forum: Beginning Holography
- Topic: No image with red laser pointer, complete n00b.
- Replies: 1
- Views: 6766
Re: No image with red laser pointer, complete n00b.
The jig to hold your laser pointer and the plate holder seem to be on carpet. You need a solid surface - a metal plate, for example - that must be secured so it doesn't rock, ie it sits solidly. The plate holder doesn't seem to have anything securing the plate. The object seems to be sitting on the ...
- Sun Sep 10, 2023 9:29 am
- Forum: DCG
- Topic: Angular Bandwidth in DCG
- Replies: 10
- Views: 14698
Re: Angular Bandwidth in DCG
Yes, true. Consider a set of Bragg planes. If the planes are all parallel from two perfectly collimated and perfectly monochromatic, sources (physically impossible), then all the Bragg planes would be at a specific angle and a specific spacing and reconstruction only happens when the reconstruction ...