@robtillaart: I'm detecting people. I'm an artist, and my work is about viewer accessibility. As the viewer walks up to the artwork, an LED at the center of the work corresponds in brightness to the distance that person is from the work--the closer the person walks, the brighter the light. The farther away, the dimmer the light gets. Ultimately, the closer the person gets and the more they try to view the artwork, the more impossible that task becomes. I need the sensor to function as far as possible to affect the greatest amount of viewers.
Attached is a crude mockup of the situation.
@jraskell: thank you! that seems very logical. i checked my serial monitor instead of relying on my other output (an LED), and the distance was 370 cm at the most, but mostly 250 cm. It's a bit farther than I thought, so that's useful in some sense!
@raron: WOW! What a great find! Now if only I can build such a magical device...
