The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Panasonic 100-300mm F4-5.6 OIS and the Olympus 75-300mm f4.8-6.7 II 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. Panasonic 100-300mm F4-5.6 OIS is the longer of the two lenses at 126mm. The Olympus 75-300mm f4.8-6.7 II with a length of 117mm, is 9mm shorter. Besides being longer, the Panasonic 100-300mm F4-5.6 OIS also has a larger diameter of 74mm compared to the Olympus 75-300mm f4.8-6.7 II's 69mm 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. Olympus 75-300mm f4.8-6.7 II weighs 423g, 18% (97g) lighter than the Panasonic 100-300mm F4-5.6 OIS's weight of 520g.
Below you can find the dimension and weight table of the Telephoto Zoom Lenses in Micro Four Thirds Mount for size comparison purposes.
Super Telephoto Lenses in Micro Four Thirds Mount for Size Comparison
Filter Threads
The Panasonic 100-300mm F4-5.6 OIS has a filter size of 67mm whereas the Olympus 75-300mm f4.8-6.7 II has a 58mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Panasonic 100-300mm F4-5.6 OIS:
And these are the 58mm filters that we recommend for the Olympus 75-300mm f4.8-6.7 II:
Lens Mounts
Both the Panasonic 100-300mm F4-5.6 OIS and the Olympus 75-300mm f4.8-6.7 II 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-1 II, Panasonic G9 II and OM System OM-5.
Focal Range
Panasonic 100-300mm F4-5.6 OIS has a focal range of 100-300mm and
3.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of
200-600mm when used on a FourThirds format camera.
On the other hand, the Olympus 75-300mm f4.8-6.7 II has a focal range of 75-300mm and 4.0X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 150-600mm when used on a FourThirds format camera.