These photographs were taken using my Canon 50D and Jim’s  Canon 75-300mm lens.
 
Canon 75-300 mm f/4.0-5.6 III USM Lens
 75mm
300mm
75mm (maybe)
300mm
300mm (closer angle)
100% crop
75mm
300mm (softer light around 5PM)
twilight
300mm taken from half a city block away.
100% crop of the sign
taken from across the street
300mm
100% crop of the helicopter
75mm low-light (slightly out of focus)
75mm