The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Olympus 150-400mm F4.5 TC 1.25x IS and the Panasonic 100-400mm F4.0-6.3 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. Olympus 150-400mm F4.5 TC 1.25x IS is the longer of the two lenses at 314mm. The Panasonic 100-400mm F4.0-6.3 with a length of 172mm, is 142mm shorter. Besides being longer, the Olympus 150-400mm F4.5 TC 1.25x IS also has a larger diameter of 116mm compared to the Panasonic 100-400mm F4.0-6.3's 83mm 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. Panasonic 100-400mm F4.0-6.3 weighs 985g, 46% (865g) lighter than the Olympus 150-400mm F4.5 TC 1.25x IS's weight of 1850g.
Below you can find the dimension and weight table of the Telephoto Zoom Lenses in Micro Four Thirds Mount for size comparison purposes.
Telephoto Zoom Lenses in Micro Four Thirds Mount for Size Comparison
Lens Mounts
Both the Olympus 150-400mm F4.5 TC 1.25x IS and the Panasonic 100-400mm F4.0-6.3 has the same Micro Four Thirds lens mount. Some of the latest released cameras that are compatible with the Micro Four Thirds lenses are OM System OM-5, Panasonic GH6 and OM System OM-1.
Focal Range
Olympus 150-400mm F4.5 TC 1.25x IS has a focal range of 150-400mm and 2.7X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 300-800mm when used on a FourThirds format camera. Panasonic 100-400mm F4.0-6.3 has a focal range of 100-400mm and 4.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 200-800mm when used on a FourThirds format camera.