The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 100-400mm f4.5-5.6L IS II USM and the Tamron AF 70-300mm f4-5.6 LD 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 100-400mm f4.5-5.6L IS II USM is the longer of the two lenses at 193mm. The Tamron AF 70-300mm f4-5.6 LD with a length of 117mm, is 76mm shorter. Besides being longer, the Canon 100-400mm f4.5-5.6L IS II USM also has a larger diameter of 94mm compared to the Tamron AF 70-300mm f4-5.6 LD's 77mm 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. Tamron AF 70-300mm f4-5.6 LD weighs 435g, 72% (1155g) lighter than the Canon 100-400mm f4.5-5.6L IS II USM's weight of 1590g.
Filter Threads
The Canon 100-400mm f4.5-5.6L IS II USM has a filter size of 77mm whereas the Tamron AF 70-300mm f4-5.6 LD has a 62mm 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 100-400mm f4.5-5.6L IS II USM:
And these are the 62mm filters that we recommend for the Tamron AF 70-300mm f4-5.6 LD:
Lens Mounts
Both the Canon 100-400mm f4.5-5.6L IS II USM and the Tamron AF 70-300mm f4-5.6 LD 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.
Tamron AF 70-300mm f4-5.6 LD is also available in Nikon F (FX) , Sony Alpha and Pentax KAF mounts.
Focal Range
Canon 100-400mm f4.5-5.6L IS II USM has a focal range of 100-400mm and
4.0X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
160 - 640mm.
On the other hand, the Tamron AF 70-300mm f4-5.6 LD has a focal range of 70-300mm and 4.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 112 - 480mm.