The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Hartblei 80mm F2.8 IF TS and the Pentax 70mm F2.4 AL L for their suitability to various photography scenarios:
Size and Weight Comparison
The weight of a lens is as important as its external dimensions, especially if you are planning to hand hold your camera and lens combination for longer periods. Pentax 70mm F2.4 AL L weighs 147g, 82% (703g) lighter than the Hartblei 80mm F2.8 IF TS's weight of 850g.
Lens Mounts
Both the Hartblei 80mm F2.8 IF TS 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 KF, Pentax K-3 III and Pentax K-1 II.
Hartblei 80mm F2.8 IF TS is also available in Canon EF , Sony Alpha and Nikon F (FX) mounts.
Pentax 70mm F2.4 AL L is also available in Pentax KAF mount.
Focal Range
Hartblei 80mm F2.8 IF TS is a prime lens with fixed focal lenght of 80mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 120mm.
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.