The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax DA 300mm F4.0 ED and the Pentax 55-300mm F4.0-5.8 ED 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. Pentax DA 300mm F4.0 ED is the longer of the two lenses at 184mm. The Pentax 55-300mm F4.0-5.8 ED with a length of 112mm, is 72mm shorter. Besides being longer, the Pentax DA 300mm F4.0 ED also has a larger diameter of 83mm compared to the Pentax 55-300mm F4.0-5.8 ED's 71mm 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. Pentax 55-300mm F4.0-5.8 ED weighs 440g, 58% (630g) lighter than the Pentax DA 300mm F4.0 ED's weight of 1070g.
Filter Threads
The Pentax DA 300mm F4.0 ED has a filter size of 77mm whereas the Pentax 55-300mm F4.0-5.8 ED 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 77mm filters that we recommend you to consider for the Pentax DA 300mm F4.0 ED:
And these are the 58mm filters that we recommend for the Pentax 55-300mm F4.0-5.8 ED:
Lens Mounts
The Pentax DA 300mm F4.0 ED has the Pentax KAF2 lens mount whereas the Pentax 55-300mm F4.0-5.8 ED has the Pentax KAF lens mount. Some of the latest released cameras that are compatible with these mounts are , and for the Pentax KAF2 Mount and Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III for the Pentax KAF Mount.
Focal Range
Pentax DA 300mm F4.0 ED is a prime lens with fixed focal lenght of 300mm which has an effective (full-frame 35mm equivalent) focal range of
450mm when used on a APS-C / DX format camera.
On the other hand, the Pentax 55-300mm F4.0-5.8 ED has a focal range of 55-300mm and 5.5X zoom ratio which has an effective (full-frame 35mm equivalent) focal range of 82.5-450mm when used on a APS-C / DX format camera.