The type of photography that you are planning to use is an important decision factor. Here we have evaluated the Leica APO-SL 75mm F2 ASPH and the Leica SL 50mm F1.4 ASPH 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. Leica SL 50mm F1.4 ASPH is the longer of the two lenses at 124mm. The Leica APO-SL 75mm F2 ASPH with a length of 102mm, is 22mm shorter. Besides being longer, the Leica SL 50mm F1.4 ASPH also has a larger diameter of 88mm compared to the Leica APO-SL 75mm F2 ASPH's 73mm 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. Leica APO-SL 75mm F2 ASPH weighs 720g, which means it is 345g (32%) lighter than the Leica SL 50mm F1.4 ASPH which has a weight of 1065g.
Below you can find the dimension and weight table of the Standard Prime Lenses in Leica L Mount for size comparison purposes.
Standard Lenses in Leica L Mount for Size Comparison
Filter Threads
The Leica APO-SL 75mm F2 ASPH has a filter size of 67mm whereas the Leica SL 50mm F1.4 ASPH has a 82mm diameter. Larger filters are generally more expensive than the smaller ones given all the other features are equal.
Below are links to the 67mm filters that we recommend you to consider for the Leica APO-SL 75mm F2 ASPH:
And these are the 82mm filters that we recommend for the Leica SL 50mm F1.4 ASPH:
Lens Mounts
Both the Leica APO-SL 75mm F2 ASPH and the Leica SL 50mm F1.4 ASPH has the same Leica L lens mount. Some of the latest released cameras that are compatible with the Leica L lenses are Leica SL3, Panasonic S5 II and Panasonic S5 II X.
Focal Range
Leica APO-SL 75mm F2 ASPH is a prime lens with fixed focal lenght of 75mm.
On the other hand, the Leica SL 50mm F1.4 ASPH is a prime lens with fixed focal lenght of 50mm.