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Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/4.0
Exposure
1/500s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/4.0
Exposure
1/640s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/4.0
Exposure
1/2000s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/4.0
Exposure
1/1250s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/4.0
Exposure
1/1000s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/5.6
Exposure
1/1250s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/4.0
Exposure
1/1000s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/5.0
Exposure
1/3200s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
320
Focal Length
300.0mm
Aperture:
f/5.6
Exposure
1/3200s
Make
Canon
Model
Canon EOS 5D Mark II
ISO Speed
200
Focal Length
300.0mm
Aperture:
f/5.0
Exposure
1/400s
Verdict
In the marketplace the Canon EF 300mm f/4 USM L IS is probably suffering from the fact that it is "only" a 300mm lens. There are numerous zoom lenses with such a tele setting out including the stiff in-house competition from the similar priced EF 100-400mm f/4.5-5.6 USM L IS and the new EF 70-300mm f/4-5.6 USM L IS. It is capable of delivering sharp results specifically in the image center. The border quality is "only" good at f/4 but you can boost it a little by stopping down to f/5.6 and f/8. The comparatively low amount of lateral CAs contribute to the high sharpness perception. Both distortions as well as vignetting are very well controlled and not really relevant in the field conditions. The quality of the bokeh is generally fine but out-of-focus highlights are somewhat nervously rendered and you may be able to spot some bokeh fringing at times.
It is worth mentioning that we've achieved a slightly higher "hit" rate in the field compared to the EF 400mm f/5.6 USM L. The IS (Image Stabilizer) simply helps a lot even in bright lighting conditions. At such long focal lengths you require very high shutter speeds in order to avoid image blurring due to shake when using such lenses without a tripod. The IS implementation on the EF 300mm f/4 USM L IS can give you an extra potential of 2 f-stops - possibly a little more due to the weight of the lens. This is less than in modern Canon IS lenses but it's very useful nonetheless. The build quality of the lens is great but that's also something that we simply expect from a lens in this price class and especially from a Canon L-class lens. The ring-type USM AF shows no weakness - it is both very fast as well as near-silent. Technically the lens is "only" about on par with Canon's L-class zoom lens offerings in this range but it offers obviously a tad more speed which is its primary differentiator.
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(Wildlife & Sports Photography) 