If someone wishes to measure light intensity there's a cheap way.
Use a Radio Shack CdS Photoresistor(about $3.00) and an ohm meter.

http://www.radioshack.com/product.asp?cata...%5Fid=276-1657#

It's obviously not going to be a high precision calibrated instrument but
will certainly indicate whether the changes or adjustments you're making
are having any effect(your eyes might not notice).

If anyone's interested, I can provide the the formula to convert the
measured resistance value of a particular sensor to a lux value. But due to
variations in sensors and accuracy of your ohm meter the lux value probably
won't mean much.

Please note the RS part consists of a package containing five different sensors,
all unmarked.