The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax-D FA645 35mm F3.5 AL IF and the Pentax D FA 645 55mm F2.8 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 FA645 35mm F3.5 AL IF is the longer of the two lenses at 90mm. The Pentax D FA 645 55mm F2.8 with a length of 68mm, is 22mm shorter. Besides being longer, the Pentax-D FA645 35mm F3.5 AL IF also has a larger diameter of 88mm 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, 27% (154g) lighter than the Pentax-D FA645 35mm F3.5 AL IF's weight of 570g.
Filter Threads
The Pentax-D FA645 35mm F3.5 AL IF has a filter size of 82mm whereas the Pentax D FA 645 55mm F2.8 has a 67mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 82mm filters that we recommend you to consider for the Pentax-D FA645 35mm F3.5 AL IF:
And these are the 67mm filters that we recommend for the Pentax D FA 645 55mm F2.8:
Lens Mounts
Both the Pentax-D FA645 35mm F3.5 AL IF and the Pentax D FA 645 55mm F2.8 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 FA645 35mm F3.5 AL IF is a prime lens with fixed focal lenght of 35mm.
On the other hand, the Pentax D FA 645 55mm F2.8 is a prime lens with fixed focal lenght of 55mm.
