Search found 401 matches

by Din
Tue Oct 03, 2023 12:54 pm
Forum: General Holography
Topic: Open aperture holograms w/lens
Replies: 2
Views: 6890

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...
by Din
Fri Sep 29, 2023 2:08 pm
Forum: General Holography
Topic: Moving the object to reduce speckle?
Replies: 9
Views: 4318

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...
by Din
Fri Sep 29, 2023 10:41 am
Forum: General Holography
Topic: Moving the object to reduce speckle?
Replies: 9
Views: 4318

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...
by Din
Thu Sep 28, 2023 1:38 pm
Forum: Off Topic
Topic: Mixed Reality
Replies: 2
Views: 3078

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, ...
by Din
Thu Sep 28, 2023 11:50 am
Forum: Off Topic
Topic: Mixed Reality
Replies: 2
Views: 3078

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...
by Din
Thu Sep 28, 2023 8:38 am
Forum: holoforum administration
Topic: Status of email service
Replies: 3
Views: 10298

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...
by Din
Tue Sep 12, 2023 8:47 am
Forum: Beginning Holography
Topic: No image with red laser pointer, complete n00b.
Replies: 1
Views: 2978

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 ...
by Din
Sun Sep 10, 2023 9:29 am
Forum: DCG
Topic: Angular Bandwidth in DCG
Replies: 10
Views: 6935

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 ...
by Din
Fri Sep 08, 2023 10:07 am
Forum: General Holography
Topic: The HUD market grows
Replies: 1
Views: 2305

The HUD market grows

The HUD market is now reaching upward of $100 million. They've come a long way from when I was making them in 1986!

https://www.insightmedia.info/automotiv ... -investor/
by Din
Fri Sep 08, 2023 10:00 am
Forum: Beginning Holography
Topic: How difficult is it to make hologram prints?
Replies: 2
Views: 2511

Re: How difficult is it to make hologram prints?

I agree it's not easy to set up your own holographic studio. It's rather specialised and expensive. Basically, you first need an environment which is largely vibration free, such as a basement with a concrete floor or a garage (there are people who'll tell you they've made holograms on a wooden floo...