Holographyforum.org / holowiki.org

Hear is a quick Vid showing screen, sorry focus is not the best and its a bit jumpy, but on the other hand I shot it a few years back?
https://www.facebook.com/video.php?v=10 ... =2&theater

great image and video! I want to do that too I made a few experiments about 7 years ago, but had no time to experiment more. Now I am back and want to give it a second try.

how did you project the image? DLP ?

TFT is a ThinFilmTransistor Screen. That is I the screen of normal a digital computer monitor without the backlight. I want to use the ground glass and afterwards the monitor screen.

I also have a dlp setup, without any motion (i remove the motor of the color wheel, and the fans) but I only have the DMD (digital Mirror device) without any focusing and magnifying optics.
I used this for computer calculated holograms.

I would recommend you do "spray frosting" search as there are a few options available in the EU, the schott glass will cost you bundle w poor results ......( I know I've tried it!)

you can also make a nice large screen using the spray on plate glass. Excellent stuff for projecting! What's a TFT screen?

What will help with the directionality issue would be to add a field lens. If you have a contemporary SLR camera, you will notice on its ground glass if you can take the lens off, a Fresnel Lens on it. This controls the image light from the lens to make a brighter viewfinder. The same principle could be applied to your diffuser.

Hm, seems that is hard to get in Germany...

I want to use it for two different methods , first for shadowgrams or as background lighting, second as a back projection plane for a TFT screen to holograph computer images.

Opalika from Schott seems to be the right thing?

there are a few manufactures of spray on frosting, I have used this with great success ! depending on the amount of frosting is needed successive coats can be applied to build up the frosting amount..

http://www.krylon.com/products/frosted-glass-finish/

what type of holograms are you making with this screen?

Ok i bought a satinized Glass, which Seems to be etched or sandblasted, because it has one rough side. Seems to work, but I have still a question, it's 30x40 cm and I light it with a small lens about 1,5 m away. If you look at the glass there is still a dependency of the angle where you look at in brightness, and you can clearly determine the round shape of the expanded beam. So it is not the reason that focus of the lens is to far and the beam size to small. But the projection screen still maintains the direction of the illuminating beam, which I think should not be the case. I assume it is because it is not a collimated beam? Or is the glass bad? Is there an other possibility to get a equally lighted screen. In the result hologram this means that the image is not equally bright from all directions. If you move right or left from center, it gets darker. It's difficult to describe, but I think you understand. So it has to be diffusing, but mine is only partly diffusing and still maintaing a big part of the original direction. Any hints?

If you mean opaque white glass by milk glass, then no. If you mean flashed opal glass by milk glass, then this could be what you are looking for.

What you call satinized would be glass that is either etched by acid or sandblasted, and it would work also. The degree of etch determines speckle size.

The flashed opal will scramble polarization, the ground glass will not. Get samples if possible and project images onto it with your laser and see which looks best to you and is the most thrifty with light.

There are specialty made screens, too, you might be able to ask for a sample that might be big enough for your purposes.

In some Books there is referred to ground glass as projection plane when making holographic sterograms

Is it milk glass , or satinized glass?