FYI

Distance between the Earth and the Sun (the big light source) : 91,000,000 - 94,000,000 miles. To increase the effect of the sun's light by one F Stop you would have to travel 46,000,000 miles toward the sun.. To decrease the effect of the sun's light by on F Stop you would have to travel 91,000,000 miles further away from the sun.

The Palm or the human hand is one stop brighter than an 18% Neutral Density Grey Card - something to consider ;o)

Twilight - not the movie - is the perfect time to create wonderful photographs.

Focal Length of a lens: http://en.wikipedia.org/wiki/Focal_length

F Stops: http://en.wikipedia.org/wiki/F-number

Depth of Field: http://en.wikipedia.org/wiki/F-number

Exposure Value: http://en.wikipedia.org/wiki/Exposure_value

Lens Flare: http://en.wikipedia.org/wiki/Lens_flare

Circle of Confusion: http://en.wikipedia.org/wiki/Circle_of_confusion

Dynamic range: http://en.wikipedia.org/wiki/Digital_photography
“Practical imaging systems, digital and film, have a limited "dynamic range "......as the sensor elements for different colors saturate in turn, there can be gross hue or saturation shift in burnt-out highlights.”

Inverse Square Law: http://en.wikipedia.org/wiki/Inverse-square_law

Metering Modes: http://en.wikipedia.org/wiki/Metering_mode

Balancing Aperture - ISO - Shutter speed Graphic

How batch process jpgs into Tiffs and how to bath process © copyrigth watermark in Photoshop elements - Link