Re: Laser pointers and reflective screens

[P3D Edward Hosey <ehh@xxxxxxxxxxxxx>]

Thanks to people who responded to this original post.  I contacted a 
couple of sources including the Laser Institute of America who put me in 
touch with an instructor at Milwaukee School of Engineering who had 
recently written a paper which discussed laser pointers.  He very kindly 
offered to listen to me regarding this issue.  His view was that my laser 
(4mW, Class IIIa, 670nm) should not pose a threat to the vision of my 
audience as long as:

1. I did not point it directly into their eyes.
2. I did not point the laser at a single spot for extended periods of 
   time (10-15 seconds) and experience "after images" when the laser was 
   turned off.

If anyone else has any input, I would appreciate hearing it.

Thanks,

Eddie

I wrote: 
>
>A friend who grew weary of me placing my hands in front of the lenses 
>of my projector to point out objects on the screen (and creating two 
>shadows pointing to different areas of the screen) gave me a laser 
>pointer as a gift.  I really like using it and was doing so without 
>concern until one of my fellow 3-D enthusiasts suggested I might be 
>risking damage to my (and my guests') eyes due to the reflective 
>qualities of the silvered screen.
>
>Anybody know whether this is likely or if a low power laser is safe (if 
>so, what level)?  Any advice you can give me will be appreciated.  I do 
>not wish to harm my friends or to be held liable for injuries sustained 
>due to my slide presentations.  Now, mounting errors and improper 
>subject matter I will take full credit for...
>
>Thanks,
>
>Eddie
-- 
Eddie Hosey
ehh@xxxxxxxxxxxxx
Take a second--breathe deeply--and think about what you enjoy most in life.


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