The type of photography that you are planning to use is an important decision factor. Here we have evaluated the OM System 40-150mm F4.0 PRO and the Panasonic 35-100mm F2.8 OIS 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. Panasonic 35-100mm F2.8 OIS is the longer of the two lenses at 100mm. The OM System 40-150mm F4.0 PRO with a length of 99mm, is 1mm shorter. On the other hand, the OM System 40-150mm F4.0 PRO has a larger diameter of 69mm compared to the Panasonic 35-100mm F2.8 OIS's 67mm 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 35-100mm F2.8 OIS weighs 360g, 5% (22g) lighter than the OM System 40-150mm F4.0 PRO's weight of 382g.
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 OM System 40-150mm F4.0 PRO and the Panasonic 35-100mm F2.8 OIS 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
OM System 40-150mm F4.0 PRO has a focal range of 40-150mm and 3.8X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 80-300mm when used on a FourThirds format camera. Panasonic 35-100mm F2.8 OIS has a focal range of 35-100mm and 2.9X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 70-200mm when used on a FourThirds format camera.