Are animated holograms possible?

On: Tue, Oct 23, 01 05:43:32 PM

Tim226 wrote:

Is the creation of animated holograms possible, and if so, how? What type of materials are needed and cost would be helpful. Thanks.
RESPONSES

Colin Kaminski - Wed, Oct 24, 01 10:53:10 AM

The short answer is yes. The long answer is you have to make some compromises. Most people choose a holographic sterogram. Simple ones can be made for a few hundred dollars worth of equipment. A top of the line holographic sterogram printer could be made for less than $3000. Once you have made a master it is more simple to copy them. Basically the process is you make a series of images is taken by a camera as it moves by the subject. An image is taken every few inches. To print the hologram you move a slit in front of your holographic film and record a hologram of each frame. Since each frame takes a few minutes at best to set up it can be very time consuming. The resulting hologram has no vertical parallax. If you try to move above the subject you can not see the top. But the 3-D effect is very convincing. I saw one of the original sterograms many years ago and was very impressed. Hobbyist have been working to expand the process to use computer generated images. I am not aware of anyone who has successfully worked out the bugs (except by taking photos of a computer screen). It is only a matter of time. All of the necessary parts are available and it will just take someone with enough time to work out the bugs. I have been working on some of the issues but I think I am a year away and expect others in this forum to get there more quickly. 63.193.192.196

Tim226 - Wed, Oct 24, 01 04:43:14 PM

Is the type of camera just an ordinary camera and the photos are placed behind the plate and made as a relection holgram? Is each frame recorded from a different angle or all straight on? How does the hologram have to be viewed? Thanks. 205.188.197.26

Colin - Wed, Oct 24, 01 11:26:30 PM

The way I have seen it done is to take the pictures with a normal camera and black and white slide film. Then the slide is projected on a piece of frosted glass with one beam of the laser replacing the slide projector bulb. The other beam is used to make a reference beam from the same side of the plate. Which means it is a transmission hologram. The reference angle is the same for all of the slits. When illuminated with laser light the viewer walks by the hologram to see the different views. If the successive frames show motion then the hologram will appear to move. I have read about using a movie camera to do this as well. You used to be able to purchase a hologram entitled "Leslie II" that used this technique. The hologram was a transmission hologram made on a cylinder. As you walked around it Leslie blew a kiss. I always thought the hologram was made flat then formed into a cylinder for viewing but I never found out for sure. I was told by a sales clerk that there were over 1000 images comprising the hologram. 63.193.192.196

Tim226 - Thu, Oct 25, 01 05:48:21 PM

Thank you very much for all your help, by the way. What do you mean by the word "slit"? How easy is it to get black and white slide film? And do you mean that these are made using a slide projector like the ones found in schools? And about how much do beam splitters go for, since this is a trnasmission hologram in oppose to a reflection. I have this theory, you can tell me if it would work...If I made a reflection hologram of what we will call "frame 1" from a very far left angle and then continued taking holograms on the same plate as each one move a little to the left but each Frame being taken in the same spot, then if the light source hit each one, in progression, would it appear to animate? Thanks 205.188.193.59

Tim226 - Thu, Oct 25, 01 05:54:01 PM

Sorry, in the second paragraph, 3rd line i said "from a very far left angle and then continued taking holograms on the same plate as each one.." the remaining should read "...moves a little to the right, but each frame being taken in the same spot on the plate, then after development, if a light source was applied in alternating, legt to right progression, would it appear to animate? Thanks" Sorry, i just noticed that didnt read right [pardon the pun], afterwards. 205.188.193.59

Colin - Thu, Oct 25, 01 11:28:01 PM

The slit is about a couple of mm wide and covers the plate so only a small line is exposed for each image. It is very important to line up each exposure so there are no gaps or double exposures or the result is visible lines. It is possible to use the whole plate to store multiple images and select them by varying the reference beam angle but you lose a great deal of efficiency. A variable beam splitter is about $75. But you could probably make a microscope slide work as a 90-10 beam splitter. You can use a real slide projector if you have room or you can make your own optics to project a real image on to the frosted glass. B&W film is available from any good camera store. I'll know more once I have tried it myself, this is only condensing what I have read. 63.193.192.196

Tim226 - Fri, Oct 26, 01 04:00:21 PM

By any chance could I have your email, because I'm sure I'll need help in the future, and it would be easier than using this forum. Thanks. 64.12.103.184

Colin - Sat, Oct 27, 01 02:02:43 PM

colinsk@pacbell.net 63.193.192.196

Chuck Hassen - Wed, Jan 30, 02 12:36:17 PM

Actually it is possible to use an LCD panel to project images instead of a film strip. Bob Hess and I did this, moving the slit in the horizontal direction for horizontal parallax, and in the vertical direction for vertical parallax and for animation with no time smear. Check the cover hologram on Holography Marketplace, 1995. There is an article on the process in there too. Chuck 63.11.141.79

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