Re: Camera software

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Elliot Burke" <elliot@...> wrote:

>
> Dennis,
> If you need wideband white noise (white in the spatial frequency sense),
> wouldn't laser speckle work for you?

good idea

> A laser beam passing through a piece of ground glass will project a
> speckle pattern. Focusing the laser beam to different sizes on the
>ground glass will change the size the speckle: small laser
>beam->large speckle, large laser beam -> small speckle. Changing the
>position of the ground glass slightly ( a fraction of the beam size)
>will change the speckle pattern completely.

I have used speckle illumination for wide field microscope systems, I
used a disk of polycarbonate (perspex is fine), ground this carefully
with some abrasive paste and mounted it on a small brushless motor.
Spinning the disk provides a constantly evolving speckle pattern, if
you spin fast enough this is averaged by the camera but if done more
slowly you see streaks. Perhaps mounting the disk on a stepper motor
so you can just change the speckle pattern as required.

3D Digitizing using cameras seems a very useful thing for lots of CNC
users.

Graham