Canon 400 mm f/2.8 to the left, Olympus Zuiko Digital 300 f/2.8 to the right. The viewing angle of the Olympus lens is the same as that of a 600 mm lens in 35 mm format. With a 1.6 crop factor camera, the 400 mm Canon lens has a viewing angle equivalent to that of a 640 mm lens on full 35 mm format. This makes the two lenses very similar when it comes to viewing angle and aperture. However, there is a marked difference in size and weight.

The Canon lens weighs 5370 g, while the Olympus lens weighs 3290 g. That's a huge weight difference. And believe me, it shows in practice. Despite the fact that the Canon lens is stabilised, it's difficult to get a clear shot at 1/500 s shutter time. With the Zuiko Digital 300/2.8, there are no such problems. The weight difference is enough that a monopod is almost required for the Canon lens. In 2002, this was the lens that demonstrated what the 4/3 system is all about - small, light lenses. The Zuiko Digital 35-100 mm f/2 is exaclty the opposite.

The Canon lens is 349 mm long. The Olympus lens, on the other hand, is only 281 mm long. This makes it much easier to work with.

Olympus E-1 and the Zuiko Digital 300 mm f/2.8.

Canon EOS D60 (1.6 crop factor) and the 400 mm f/2.8 lens.

Olympus to the left, Canon to the right. 100% crops.

Olympus E-1 and the Zuiko Digital 300 mm f/2.8.

Canon Eos D60 (1.6 crop factor) and the 400 mm f/2.8 lens.

Olympus to the left, Canon to the right. 100% crops.

Olympus to the left, Canon to the right. 100% crops. The Canon image is downsampled to match the Olympus image in size

The original shot.

Olympus to the left, Canon to the right, at 1/500 s, no monopod or tripod, 100% crops. Despite using the IS feature on the Canon lens, it was difficult to get a clear shot. With the Zuiko Digital 300 mm f/2.8, it wasn't a problem.