In this Lens Review we’re taking a look at the Canon 300mm f/4 L IS USM telephoto prime lens. The focal length of 300mm is extremely popular among nature, wildlife and MotorSport photographers. This lens offers superb image quality and awesome L Series features, and all this quality makes this Canon 300mm f4 potentially one of the best telephoto lenses you can get for your money. 

At 300mm there is a lot of image compression when it comes to perspective, this means that you can get some impressive subject isolation even with the f/4 aperture. Backgrounds will be out of focus with nice smooth bokeh whilst the subject will be nice and sharp.

With an f/4 maximum aperture the lens may struggle to freeze action in low light, however there image stabilisation that will give you 2 stops of compensation, this is especially important when shooting hand held. Image Stabilisation won’t help with moving subjects but it will take out some of camera shake when taking photos in low light or with slower shutter speeds.

The auto focus on this lens is incredibly fast and accurate. I used this lens mainly for motorsport where the subject can be approaching a speeds over a 100mph and I had no problems maintaining focus when in AI Servo mode.

This lens is also very sharp when shooting wide open at f4, with the image quality improving further when you stop down to f/5.6, there is good sharpness in the corners of the image even on a full frame camera like the Canon 5D Mark III that we tested it on.

So how does this lens stack up? Watch our detailed lens review for more information, this video contains sample video footage and images captured with this lens:

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