The type of photography that you are planning to use is an important decision factor. Here we have evaluated the OM System 90mm F3.5 Macro and the Canon 180mm f3.5L Macro USM 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 180mm f3.5L Macro USM is the longer of the two lenses at 187mm. The OM System 90mm F3.5 Macro with a length of 136mm, is 51mm shorter. Besides being longer, the Canon 180mm f3.5L Macro USM also has a larger diameter of 83mm compared to the OM System 90mm F3.5 Macro's 70mm 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. OM System 90mm F3.5 Macro weighs 453g, which means it is 637g (58%) lighter than the Canon 180mm f3.5L Macro USM which has a weight of 1090g.
Filter Threads
The OM System 90mm F3.5 Macro has a filter size of 62mm whereas the Canon 180mm f3.5L Macro USM has a 72mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the OM System 90mm F3.5 Macro:
And these are the 72mm filters that we recommend for the Canon 180mm f3.5L Macro USM:
Lens Mounts
The OM System 90mm F3.5 Macro has the Micro Four Thirds lens mount whereas the Canon 180mm f3.5L Macro USM has the Canon EF lens mount. Some of the latest released cameras that are compatible with these mounts are OM System OM-1 II, Panasonic G9 II and OM System OM-5 for the Micro Four Thirds Mount and Canon 1D X III, Canon 6D MII and Canon 5D MIV for the Canon EF Mount.
Focal Range
OM System 90mm F3.5 Macro is a prime lens with fixed focal lenght of 90mm which has an effective (full-frame 35mm equivalent) focal range of
180mm when used on a FourThirds format camera.
On the other hand, the Canon 180mm f3.5L Macro USM is a prime lens with fixed focal lenght of 180mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of 288mm.