Light Lens Lab 50mm F1.5 Z21

The Light Lens Lab 50mm f/1.5 Z21 is a manual full-frame standard prime for Leica M-mount cameras. Light Lens Lab describes it as a homage to the legendary 50mm f/1.5 S21 and says it closely follows the original element design and performance characteristics. It was the start of the company's Z21 line.

Optical design

The lens has six elements in four groups. According to Light Lens Lab, the design shows improvements in contrast and line transfer compared with the original, and it supports frame coverage up to 44 by 33 mm on a digital sensor. The company also states that significant changes were made to the original design, that the elements are made in house, and that they are infused with lanthanides specifically designed for this lens. The maximum aperture is f/1.5, and the aperture runs down to f/22.

Focusing and handling

Focusing is manual, with rangefinder coupling and a minimum focus distance of 0.7 m. There is no autofocus. The filter thread is E52. The mount is a quick-change M-mount bayonet. Light Lens Lab says each lens is handcrafted and assembled in limited quantities with strict quality control.

Build and size

The body is aluminium. The lens weighs 313 g, is 64.2 mm long and has a diameter of 60.7 mm. Those numbers are published by the manufacturer on the product page. They make it larger than the company's f/2 lenses but still small for an f/1.5 normal lens.

Where it fits

Light Lens Lab's 75mm f/1.5 Z21 is a later model in the same Z21 line, aimed at a longer focal length. For 50 mm lenses on M-mount, the database lists many alternatives, including the Leica Summilux-M 50mm f/1.4 ASPH, the Leica Summicron-M 50mm f/2, the Leica APO-Summicron-M 50mm f/2 ASPH, the Leica Summarit-M 50mm F2.4 ASPH, the Voigtlander 50mm F1.5 Nokton VM II, the Voigtlander 50mm F1.1 Nokton, the Thypoch Simera 50mm F1.4 and the TTArtisan 50mm f/1.4 ASPH. Light Lens Lab's recreation approach is unlike most of those lenses, which follow current optical designs.

Pros and cons

Pros

• Fast f/1.5 aperture in a compact body
• Six elements in four groups, with lanthanide-infused elements according to the maker
• Frame coverage stated up to 44 by 33 mm
• Fully published size and weight data
• Aluminium body

Cons

• Manual focus only
• 313 g is heavier than the company's f/2 options
• The optical formula is described only in general terms by the maker
• Limited production, according to Light Lens Lab

Verdict

The 50mm f/1.5 Z21 is an f/1.5 normal lens for M-mount users who like a vintage inspired design with clear published specifications. It combines a fast aperture with compact dimensions, and it is a good reference point for judging the faster alternatives in the database.