The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 300mm f4.0L IS USM and the Sigma 300mm F2.8 APO EX DG HSM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is a crucial factor to consider when comparing two lenses. Canon 300mm f4.0L IS USM is the longer of the two lenses at 221mm. The Sigma 300mm F2.8 APO EX DG HSM with a length of 215mm, is 6mm shorter. On the other hand, the Sigma 300mm F2.8 APO EX DG HSM has a larger diameter of 119mm compared to the Canon 300mm f4.0L IS USM's 90mm diameter.
The weight of a lens is equally significant as its external dimensions, particularly if you intend to handhold your camera and lens combination for extended periods. Canon 300mm f4.0L IS USM weighs 1190g, which means it is 1210g (50%) lighter than the Sigma 300mm F2.8 APO EX DG HSM which has a weight of 2400g.
Below you can find the dimension and weight table of the Telephoto Prime Lenses in Canon EF Mount for size comparison purposes.
Telephoto Lenses in Canon EF Mount for Size Comparison
Filter Threads
The Canon 300mm f4.0L IS USM has a filter size of 77mm whereas the Sigma 300mm F2.8 APO EX DG HSM has a 46mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 77mm filters that we recommend you to consider for the Canon 300mm f4.0L IS USM:
And these are the 46mm filters that we recommend for the Sigma 300mm F2.8 APO EX DG HSM:
Lens Mounts
Both the Canon 300mm f4.0L IS USM and the Sigma 300mm F2.8 APO EX DG HSM has the same Canon EF lens mount. Some of the latest released cameras that are compatible with the Canon EF lenses are Canon 1D X III, Canon 6D MII and Canon 5D MIV.
Sigma 300mm F2.8 APO EX DG HSM is also available in Nikon F (FX) , Pentax KAF, Sony Alpha and Sigma SA mounts.
Focal Range
Both lenses have the same focal range of
300mm but while Canon 300mm f4.0L IS USM has the fastest aperture of
F4.0, the Sigma 300mm F2.8 APO EX DG HSM's widest aperture value is
F2.8.