The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Pentax 35mm F2.8 Macro L and the Pentax 40mm F2.8 L 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 35mm F2.8 Macro L is the longer of the two lenses at 47mm. The Pentax 40mm F2.8 L with a length of 15mm, is 32mm shorter. On the other hand, there is no difference between the max diameters of these lenses, both coming at 63mm.
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 40mm F2.8 L weighs 90g, 57% (124g) lighter than the Pentax 35mm F2.8 Macro L's weight of 214g.
Filter Threads
Both the Pentax 35mm F2.8 Macro L and the Pentax 40mm F2.8 L have the same Filter thread size of 49mm.
Below are links to the 49mm filters that we recommend you to consider for these lenses:
Lens Mounts
Both the Pentax 35mm F2.8 Macro L and the Pentax 40mm F2.8 L has the same Pentax KAF lens mount. Some of the latest released cameras that are compatible with the Pentax KAF lenses are Pentax K-3 III Monochrome, Pentax KF and Pentax K-3 III.
Pentax 35mm F2.8 Macro L is also available in Pentax KAF mount.
Pentax 40mm F2.8 L is also available in Pentax KAF mount.
Focal Range
Pentax 35mm F2.8 Macro L is a prime lens with fixed focal lenght of 35mm which has an effective (full-frame 35mm equivalent) focal range of
52.5mm when used on a APS-C / DX format camera.
On the other hand, the Pentax 40mm F2.8 L is a prime lens with fixed focal lenght of 40mm which has an effective (full-frame 35mm equivalent) focal range of 60mm when used on a APS-C / DX format camera.