8 sec @ f32, ISO100, 59mm (zoom), Canon 20D
Created by zooming in during the shot of a fairground ride.

1/400 sec @f11, ISO200, 24mm (zoom), Canon 20D
A triangle created by perspective, shooting upwards of course. The tower at the Tate Modern.
1/160 sec @ f16, ISO400, 22mm (zoom), Canon 20D
An inverted triangle, partially created by pointing a wide angle lens downwards. American Civil War cemetary.