My second hologram (Circuit board)

Present your work.
kyodai

My second hologram (Circuit board)

Post by kyodai »

OK so here is my second try, an old circuit board. Was once one of the hottest graphics cards, but today only resting on a shelf. Becoming my newest model for holography the card somehow came to life again in a different meaning of 3D graphics.

What i noticed is that the background is quite unsharp - kinda cool but i guess this is a limitation of the reflection technique or laser?

Image



And a video again:


http://www.youtube.com/watch?v=GEM9yw4Vm9c
Arturo
Posts: 126
Joined: Thu Jan 08, 2015 4:48 am

My second hologram (Circuit board)

Post by Arturo »

Any changes in setup or exposure from the first one?
kyodai

My second hologram (Circuit board)

Post by kyodai »

No, i made it with exactly the same setup as the first one. The first one did not have depth on the object however so it was probably simply not visible. It's like the focus is directly on par with the emulsion and getting defucused slightly the further away from the emulsion. Maybe my laser is too far away from the object?
Dinesh

My second hologram (Circuit board)

Post by Dinesh »

kyodai wrote:It's like the focus is directly on par with the emulsion and getting defucused slightly the further away from the emulsion. Maybe my laser is too far away from the object?
No, you're laser is not too far away from the object. When you reconstruct with white light, the sharpness of the object depends on how far away it is from the plane of the film - the image plane. The further away the object is, the more blurred it is. If you reconstruct with laser light, this is still true, but you have to go a long way before you notice any blurring.

The reason is that you're reconstructing it with light with many different wavelengths (the whole white light spectrum!). The hologram "chooses" a few of these wavelengths to 'give back' to you as an image light (the 'few wavelengths' it gives back is called the bandwidth of the hologram). But, each of those 'few wavelengths' - the bandwidth - diffracts through very small changes in angle. So, if you're image contains wavelengths from 520 to 530, then the 520 component may diffract at 60 degrees, the 522 may diffract at 60.1 degrees, the 526 may diffract at 60.4 degrees etc. These small changes in angle means that light from any part of the image is coming at you from a small range of angles and so the image is blurred. These angles - the range of angles - gets larger as the image is further from the image plane and so the image gets more blurred. The reason that a laser "allows' a deeper sharper image is that there are fewer wavelengths in a laser.
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