The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon MP-E 65mm f2.5 1-5x Macro and the Canon 100mm f2.8 Macro 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 100mm f2.8 Macro USM is the longer of the two lenses at 119mm. The Canon MP-E 65mm f2.5 1-5x Macro with a length of 98mm, is 21mm shorter. On the other hand, the Canon MP-E 65mm f2.5 1-5x Macro has a larger diameter of 81mm compared to the Canon 100mm f2.8 Macro USM's 79mm 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 100mm f2.8 Macro USM weighs 600g, 15% (110g) lighter than the Canon MP-E 65mm f2.5 1-5x Macro's weight of 710g.
Below you can find the dimension and weight table of the Macro Prime Lenses in Canon EF Mount for size comparison purposes.
Macro Prime Lenses in Canon EF Mount for Size Comparison
Lens Mounts
Both the Canon MP-E 65mm f2.5 1-5x Macro and the Canon 100mm f2.8 Macro 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 MP-E 65mm f2.5 1-5x Macro is a prime lens with fixed focal lenght of 65mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 104mm.
Canon 100mm f2.8 Macro USM is a prime lens with fixed focal lenght of 100mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 160mm.