The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax D FA 645 55mm F2.8 and the Pentax D FA 645 25mm F4 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 D FA 645 25mm F4 is the longer of the two lenses at 140mm. The Pentax D FA 645 55mm F2.8 with a length of 68mm, is 72mm shorter. Besides being longer, the Pentax D FA 645 25mm F4 also has a larger diameter of 90mm compared to the Pentax D FA 645 55mm F2.8's 81mm 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 D FA 645 55mm F2.8 weighs 416g, which means it is 654g (61%) lighter than the Pentax D FA 645 25mm F4 which has a weight of 1070g.
Filter Threads
The Pentax D FA 645 55mm F2.8 has a filter size of 67mm whereas the Pentax D FA 645 25mm F4 has a 41mm 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 Pentax D FA 645 55mm F2.8:
And these are the 41mm filters that we recommend for the Pentax D FA 645 25mm F4:
Lens Mounts
Both the Pentax D FA 645 55mm F2.8 and the Pentax D FA 645 25mm F4 has the same Pentax 645AF2 lens mount. Some of the latest released cameras that are compatible with the Pentax 645AF2 lenses are Pentax 645Z, Pentax 645D and .
Focal Range
Pentax D FA 645 55mm F2.8 is a prime lens with fixed focal lenght of 55mm.
On the other hand, the Pentax D FA 645 25mm F4 is a prime lens with fixed focal lenght of 25mm.
