The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Samyang 85mm F1.4 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. Samyang 85mm F1.4 is the longer of the two lenses at 75mm. The Pentax 70mm F2.4 AL L with a length of 26mm, is 49mm shorter. Besides being longer, the Samyang 85mm F1.4 also has a larger diameter of 78mm 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 130g, 75% (409g) lighter than the Samyang 85mm F1.4's weight of 539g.
Filter Threads
The Samyang 85mm F1.4 has a filter size of 72mm 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 72mm filters that we recommend you to consider for the Samyang 85mm F1.4:
And these are the 49mm filters that we recommend for the Pentax 70mm F2.4 AL L:
Lens Mounts
Both the Samyang 85mm F1.4 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.
Samyang 85mm F1.4 is also available in Canon EF , Nikon F (FX), Four Thirds, Sony Alpha, Sony E and Samsung NX mounts.
Pentax 70mm F2.4 AL L is also available in Pentax KAF mount.
Focal Range
Samyang 85mm F1.4 is a prime lens with fixed focal lenght of 85mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of
127.5mm.
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.