sizes of projected image compared to size of plate

Valentin · Post by **Valentin** » Wed Mar 10, 2004 9:52 am

What is the relation ship between the size of the projected image and the holographic plate?Do the object and plate always have to be the same size?For example is it possible to capture a large object like a car, on a small plate, 20 x 48 or whatever the standard size is. I assume that you would have to place the object far from the plate during exposure. So the laser output would have to be high. In that case would it also be possible to have image projected far away from the plate during display.

Turanchox · Post by **Turanchox** » Sun Mar 14, 2004 5:11 pm

Unfortunately, scaling in a holography is quite difficult and expensive procedure. It's necessary to use complex optics, in order to change scale of the image within a hologram.
The solution is multiplex holography, when you shoot several photographic images in order to "collect" a hologram.If you just place the big object far from the holographic plate, there is a chance, when laser's coherence length is not enough.

Val · Post by **Val** » Mon Mar 15, 2004 8:44 am

So then with a laser with a sufficient coherence length and power this can be achieved by placing the object far?Also what kind of optics are you talking about here. Is there a link or reading material I should look at?

Turanchox · Post by **Turanchox** » Mon Mar 15, 2004 8:26 pm

None of lasers has sufficient coherence length, and there are no photomaterials to register such a deep scene. Unfortunately, I'd like to underline. Anyway, you need some scaling "mechanism" in order to register large objects. The optics is, first of all, special big objective, which is very expensive. If you even have this objective, quality losses are significant.