Re: [photo-3d] How large an image can a TDC (standard lenses) project?

["Dr. George A. Themelis" <drt-3d@xxxxxxx>]

Grant Campos wrote:

> As I'm planning for my new screen, I am wondering what the formula is 
> for distance vs. size for the standard lenses on the TDC 116

Simple geometry problem of similar triangles.  In one side you
have your 5" lenses (FL for focal length of the lens) and a roughly 
1" tall image (IS for image size).  In the other side you have the 
distance from the projector X and the size of the screen S.  I believe 
from similar triangles you get:

FL/IS = X/S, or, in your case,  X = 5 S.

Example, to fill a 6 foot tall screen (72") you must set the projector
at roughly 30 feet from the screen.  I hope this is correct as I
never use math for these things! :)

> what is the limit to how far back I can get with my TDC 116? 

There is no physical limit but I trust the reduction in brightness
will be the limiting factor, according to your taste.

George




 

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