The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Lensbaby Sol 45 DSLR 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. Lensbaby Sol 45 DSLR is the longer of the two lenses at 39mm. The Pentax 40mm F2.8 L with a length of 15mm, is 24mm shorter. Besides being longer, the Lensbaby Sol 45 DSLR also has a larger diameter of 73mm compared to the Pentax 40mm F2.8 L's 63mm 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 40mm F2.8 L weighs 80g, 44% (64g) lighter than the Lensbaby Sol 45 DSLR's weight of 144g.
Lens Mounts
Both the Lensbaby Sol 45 DSLR 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.
Lensbaby Sol 45 DSLR is also available in Canon EF , Fujifilm X, Nikon F (FX) and Sony Alpha mounts.
Pentax 40mm F2.8 L is also available in Pentax KAF mount.
Focal Range
Lensbaby Sol 45 DSLR is a prime lens with fixed focal lenght of 45mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
67.5mm.
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.