The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Sony DT 50mm F1.8 SAM and the Hartblei 40mm F4 IF TS 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. Sony DT 50mm F1.8 SAM weighs 170g, which means it is 1380g (89%) lighter than the Hartblei 40mm F4 IF TS which has a weight of 1550g.
Lens Mounts
Both the Sony DT 50mm F1.8 SAM and the Hartblei 40mm F4 IF TS has the same Sony Alpha lens mount. Some of the latest released cameras that are compatible with the Sony Alpha lenses are Sony A68, Sony A77 II and Sony A58.
Hartblei 40mm F4 IF TS is also available in Canon EF , Pentax KAF and Nikon F (FX) mounts.
Focal Range
Sony DT 50mm F1.8 SAM is a prime lens with fixed focal lenght of 50mm which has an effective (full-frame 35mm equivalent) focal range of 75mm when used on a APS-C / DX format camera. Hartblei 40mm F4 IF TS is a prime lens with fixed focal lenght of 40mm. When it is mounted on an APS-C sensor camera with 1.5x crop, it provides a 35mm (FF) equivalent of 60mm.