I was curious if anyone has thought of the following way to
>reduce image noise, in particular noise that comes from an
>electromagnetic source i.e. not light. The idea is,
>just cover most of the camera with tinfoil, everything except
>the lens of course. By this method, the only signal noise
>that affects the analog sensor elements will be of either
>internal origin (the circuits) or optical.
>But will it work? I haven't tried it, since I temporarily don't
>have a digital camera.
The noise comes from the sensor and the electronics, not from radio signals around you.
You can reduce noise by cooling the camera. That reduces in the sensor and electronics. Don't cool below freezing, though, because then the battery will fail.