Hi,

For the application you have described, why not use LDRs instead of LEDs? They give a far more linear response over a wider spectrum.

Also, in my experience, the pot command used on different pins give a different reading. That is, for the same intensity, and even assuming all 4 of your LDRs are charachteristically identical, you are likely to get different readings on different pins, even on the same port.

Look at this thread for a possible solution: http://www.picbasic.co.uk/forum/showthread.php?p=70591

To avoid these hassles, why not use a pic with ADCs?

Regards,

Anand Dhuru