The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon 35-80mm f4.0-5.6 III and the Canon 28-135mm f3.5-5.6 IS USM for their suitability to various photography scenarios:
Size and Weight Comparison
The size of a lens is an important deciding factor when comparing two lenses. Canon 28-135mm f3.5-5.6 IS USM is the longer of the two lenses at 97mm. The Canon 35-80mm f4.0-5.6 III with a length of 64mm, is 33mm shorter. Besides being longer, the Canon 28-135mm f3.5-5.6 IS USM also has a larger diameter of 78mm compared to the Canon 35-80mm f4.0-5.6 III's 65mm diameter.
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Canon 35-80mm f4.0-5.6 III weighs 175g, which means it is 365g (67%) lighter than the Canon 28-135mm f3.5-5.6 IS USM which has a weight of 540g.
Below you can find the dimension and weight table of the Standard Zoom Lenses in Canon EF Mount for size comparison purposes.
Standard Zoom Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Canon 35-80mm f4.0-5.6 III and the Canon 28-135mm f3.5-5.6 IS USM 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.
Focal Range
Canon 35-80mm f4.0-5.6 III has a focal range of 35-80mm and 2.3X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 56 - 128mm.
Canon 28-135mm f3.5-5.6 IS USM has a focal range of 28-135mm and 4.8X zoom ratio . When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 44.8 - 216mm.