DK-Optic Impastolite 51mm F1.5

The DK-Optic Impastolite 51mm F1.5 is a manual focus standard lens for Leica M-mount cameras and covers full frame. DK-Optic presents it as a recreation of the mid-20th-century British 50mm f/1.5 known as the Septac. It is aimed at photographers who want a vintage, painterly rendering on a modern body. It was introduced in November 2025.

Optical design

The lens has 7 elements in 5 groups. According to DK-Optic, it is a 1:1 recreation of the original with no modern optical additives, built from new old stock optical glass. The black version has an amber coating, and the silver version is uncoated for a more vintage look with stronger flare. The aperture runs from f/1.5 to f/11 with 18 blades. DK-Optic claims a "glow" and swirly bokeh wide open, and better contrast and resolving power once stopped down. These are manufacturer statements.

Focusing and handling

Focusing is manual with a rangefinder coupled helicoid, and the minimum focus distance is 0.7 m. The aperture is a manual preset that is dampened and calibrated, according to DK-Optic. The helicoid and the aperture mechanics are machined from brass.

Build and size

The barrel is made of 7075 aluminium with a brass helicoid. The lens is 46 mm long when mounted, 54 mm wide and weighs 179 g without caps. A threaded metal hood is included, together with a metal front cap and a presentation box. The filter size is listed as 43 mm on the lens body, 46 mm on the hood and 49 mm.

Where it fits

The focal length is 51 mm, so it sits next to the usual 50 mm options. Among fast Leica M standard lenses in our database are the Voigtlander 50mm F1.5 Nokton VM II, the Voigtlander 50mm F1.1 Nokton and the Leica Summilux-M 50mm f/1.4 ASPH. They aim for modern correction, while the Impastolite aims for character.

Pros and cons

Pros

• Fast f/1.5 aperture in a small and light body
• 18 aperture blades for round highlights
• Rangefinder coupling and full frame coverage
• Two coating versions for different looks

Cons

• Manual focus only
• Minimum focus distance of 0.7 m
• Designed for character, not for clinical sharpness, according to the maker

Verdict

The Impastolite is a niche lens for Leica M users who want the look of a classic 50 mm f/1.5 recreated with modern mechanics. It makes sense if rendering matters more than corrected optics. If you need a neutral standard lens, one of the other 50 mm options in the database is the safer pick.