The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Lensbaby Burnside 35 and the Pentax 70mm F2.4 AL 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 Burnside 35 is the longer of the two lenses at 70mm. The Pentax 70mm F2.4 AL L with a length of 26mm, is 44mm shorter. Besides being longer, the Lensbaby Burnside 35 also has a larger diameter of 70mm compared to the Pentax 70mm F2.4 AL 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 70mm F2.4 AL L weighs 147g, 60% (227g) lighter than the Lensbaby Burnside 35's weight of 374g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Pentax KAF Mount for size comparison purposes.
Standard Lenses in Pentax KAF Mount for Size Comparison
Filter Threads
The Lensbaby Burnside 35 has a filter size of 62mm whereas the Pentax 70mm F2.4 AL L has a 49mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 62mm filters that we recommend you to consider for the Lensbaby Burnside 35:
And these are the 49mm filters that we recommend for the Pentax 70mm F2.4 AL L:
Lens Mounts
Both the Lensbaby Burnside 35 and the Pentax 70mm F2.4 AL 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 Burnside 35 is also available in Canon EF , Fujifilm X, Micro Four Thirds, Nikon F (FX), Samsung NX, Sony Alpha and Sony E mounts.
Pentax 70mm F2.4 AL L is also available in Pentax KAF mount.
Focal Range
Lensbaby Burnside 35 is a prime lens with fixed focal lenght of 35mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
52.5mm.
On the other hand, the Pentax 70mm F2.4 AL L is a prime lens with fixed focal lenght of 70mm which has an effective (full-frame 35mm equivalent) focal range of 105mm when used on a APS-C / DX format camera.