Rob:

Thanks for your contribution to this thread.

Thanks also for your tag line: "It's all about the light."

I agree, I agree ... !

I have been criticized for teaching that there are four variables involved in arriving at the desired exposure: Aperture, Shutter Speed, and Illumination. Every camera with any automatic exposure capability (A, S, P, etc.) executes some version of the simple equation that integrates these four variables. Given any three of the variables, it is relatively simple arithmetic to calculate the fourth.

Apparently some are teaching that illumination is not part of the exposure calculation process. I have been told by some, that they only teach aperture and shutter speed, ignoring ISO and illumination completely. Granted, some students have a tough time wrapping their heads around the exposure issue. I believe students should be exposed to all four variables at the same time, and it is up to the instructor to explain their relationships and integration into the exposure calculation.

In my personal view, illumination is the sine qua non of photography: Without illumination there can be no photography. I would be misleading students if I ignored illumination.

Regards,

HBB in Phoenix, Arizona
Nikonian Team Member

Photography is a journey with no conceivable destination.