Canon Canon EF Prime

EF 300mm f/4L IS USM + 1.4x extender

300mm
f/300.0
Prime

Quick answer

The Canon EF 300mm f/4L IS USM + 1.4x extender is a telephoto prime lens covering 300mm at f/300.0 for the Canon EF mount. Its smaller maximum aperture favours daylight shooting and keeps the lens compact.

About this lens

This 300mm f/4 telephoto prime lens from Canon fits Canon EF mount cameras, from the Canon L series with Image Stabilizer and ultrasonic-motor autofocus. A relatively portable L-series telephoto prime for wildlife and sports.

Canon EF 300mm f/4L IS USM + 1.4x extender specifications

Brand: Canon
Mount: Canon EF
Focal length: 300mm
Maximum aperture: f/300.0
Lens type: Prime

What can you shoot with the Canon EF 300mm f/4L IS USM + 1.4x extender?

At 300mm this is a telephoto prime, which typically suits:

Sports and action
Wildlife and birds at moderate distance
Compressing distant landscapes

Its smaller maximum aperture favours daylight shooting and keeps the lens compact.

Full-frame equivalent and field of view

Calculated from the focal length and crop factor. Not measured.

Sensor	Crop	Equivalent	Horizontal FOV	Diagonal FOV
Full frame	1.0x	300mm	6.9°	8.2°
APS-C	1.6x	480mm	4.3°	5.2°

Try the field-of-view calculator

Frequently asked questions

What mount does the Canon EF 300mm f/4L IS USM + 1.4x extender use?

It uses the Canon EF mount, so it fits Canon EF cameras directly.

What is the focal length of the Canon EF 300mm f/4L IS USM + 1.4x extender?

It is a fixed 300mm lens with a maximum aperture of f/300.0. That makes it a telephoto lens.

Is the Canon EF 300mm f/4L IS USM + 1.4x extender a prime or a zoom lens?

It is a prime lens with a fixed 300mm focal length. Primes usually open wider than zooms; this one opens to f/300.0.

What is the Canon EF 300mm f/4L IS USM + 1.4x extender equivalent on a crop sensor?

On APS-C (1.6x crop) it frames like 480mm on full frame, with a 4.3° horizontal and 5.2° diagonal field of view. These figures are calculated from the focal length and crop factor.