Re: fun things to try / laser pen questions

[P3D Larry Berlin <lberlin@xxxxxxxxx>]

>Date: Thu, 14 Nov 1996 09:45:36 -0500
>From: P3D John W Roberts writes:
>
>I've taken 3D photos at night, with the camera shutters open and a
>(helium-neon) laser used to "scan" over a still scene in various patterns.
>The result doesn't look like much in 2D, but in 3D much of the depth
>information can be reconstructed. It's comparable to making a "wire mesh"
>image by photographic means rather than by computer modeling.

******************  Wow, great idea. It's amazing how easy some of the
alternatives to complete computer reconstruction are which exist in stereo
photography. I like this one a lot! Such stereo laser traced photo-meshes
would provide easy accurate means of assigning coordinate points in the
software that converts stereo photos to 3D models. Although to be fair, it
may be just as easy to project any slide image with a strong contrasting
texture or grid onto an object which is then photo'd in 3D. Any strong
texturing would make coordinating depth points easy.


>
>My question: how well do typical color slide and negative films respond at
>these wavelengths? The He-Ne laser worked pretty well with color negative
>film. From a photographic standpoint, is paying a few tens of dollars more
>for a 635 nm laser pen (compared to the cost of a 670 nm model) justified
>by increased sensitivity of the film at that wavelength? (Further question -
>anyone know the spectral sensitivity of typical consumer CCD video cameras?)
>
>John R
>
>

****************  What's the price range of the 635 nm pointers you've found?

Larry Berlin

Email: lberlin@xxxxxxxxx
http://www.sonic.net/~lberlin/
http://3dzine.simplenet.com/


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