Exposure

Hey guys,

a couple of years ago I came across a video series on Vimeo that explained exposure, metering and the grey scale in a very easy to understand format. I bought my girlfriend a camera for Christmas (her first dslr) and I am having troubles explaining exposure and the relationship that iso, shutter speed and aperture have. Just wondering if anyone knows which video series I am talking about and where to find it again.

thanks,

josh