The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Olympus ED 100-400mm F5.0-6.3 IS and the Olympus 300mm F4 IS Pro 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. Olympus 300mm F4 IS Pro is the longer of the two lenses at 227mm. The Olympus ED 100-400mm F5.0-6.3 IS with a length of 206mm, is 21mm shorter. Besides being longer, the Olympus 300mm F4 IS Pro also has a larger diameter of 93mm compared to the Olympus ED 100-400mm F5.0-6.3 IS's 86mm 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 ED 100-400mm F5.0-6.3 IS weighs 1120g, which means it is 150g (11%) lighter than the Olympus 300mm F4 IS Pro which has a weight of 1270g.
Filter Threads
The Olympus ED 100-400mm F5.0-6.3 IS has a filter size of 72mm whereas the Olympus 300mm F4 IS Pro 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 72mm filters that we recommend you to consider for the Olympus ED 100-400mm F5.0-6.3 IS:
And these are the 77mm filters that we recommend for the Olympus 300mm F4 IS Pro:
Lens Mounts
Both the Olympus ED 100-400mm F5.0-6.3 IS and the Olympus 300mm F4 IS Pro 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
Olympus ED 100-400mm F5.0-6.3 IS 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.
On the other hand, the Olympus 300mm F4 IS Pro is a prime lens with fixed focal lenght of 300mm which has an effective (full-frame 35mm equivalent) focal range of 600mm when used on a FourThirds format camera.