The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Canon EF 400mm F2.8L IS III USM and the Panasonic Leica DG Elmarit 200mm F2.8 Power OIS 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 EF 400mm F2.8L IS III USM is the longer of the two lenses at 343mm. The Panasonic Leica DG Elmarit 200mm F2.8 Power OIS with a length of 174mm, is 169mm shorter. Besides being longer, the Canon EF 400mm F2.8L IS III USM also has a larger diameter of 163mm compared to the Panasonic Leica DG Elmarit 200mm F2.8 Power OIS's 88mm 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. Panasonic Leica DG Elmarit 200mm F2.8 Power OIS weighs 1245g, 56% (1595g) lighter than the Canon EF 400mm F2.8L IS III USM's weight of 2840g.
Filter Threads
The Canon EF 400mm F2.8L IS III USM has a filter size of 52mm whereas the Panasonic Leica DG Elmarit 200mm F2.8 Power OIS has a 77mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 52mm filters that we recommend you to consider for the Canon EF 400mm F2.8L IS III USM:
And these are the 77mm filters that we recommend for the Panasonic Leica DG Elmarit 200mm F2.8 Power OIS:
Lens Mounts
The Canon EF 400mm F2.8L IS III USM has the Canon EF lens mount whereas the Panasonic Leica DG Elmarit 200mm F2.8 Power OIS has the Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with these mounts are Canon 1D X III, Canon 6D MII and Canon 5D MIV for the Canon EF Mount and OM System OM-1 II, Panasonic G9 II and OM System OM-5 for the Micro Four Thirds Mount.
Focal Range
Canon EF 400mm F2.8L IS III USM is a prime lens with fixed focal lenght of 400mm. When it is mounted on an APS-C sensor camera with 1.6x crop, it provides a 35mm (FF) equivalent of
640mm.
On the other hand, the Panasonic Leica DG Elmarit 200mm F2.8 Power OIS is a prime lens with fixed focal lenght of 200mm which has an effective (full-frame 35mm equivalent) focal range of 400mm when used on a FourThirds format camera.