Brightin Star APO 35mm f/1.7 ASPH

Brightin Star APO 35mm f/1.7 ASPH

The APO 35mm f/1.7 ASPH is a wide-angle manual-focus lens for the Leica M bayonet, produced by Brightin Star from 2026. Its naming combines two design claims common to current third-party M lenses: an apochromatic (APO) correction intended to control chromatic aberration, and at least one aspherical (ASPH) element. The optical system uses eleven elements arranged in seven groups, a relatively complex layout for a 35mm lens of this speed.

The lens is physically compact, measuring 43 mm in length and about 53 mm in diameter, with a weight of 266 g, which keeps it in line with the small handling that suits rangefinder bodies. The aperture is built from eleven blades, a high count that yields a rounded opening through the aperture range. Minimum focus is 0.3 m, closer than the roughly 0.7 m typical of classic rangefinder-coupled lenses; this reflects that the lens is not rangefinder coupled, so focusing is set by scale or, in practice, by live view or a focusing aid on mirrorless and digital bodies rather than by the camera's rangefinder mechanism. It is offered in black, without six-bit coding, so a camera will not read lens identification automatically.

Because it lacks rangefinder coupling and six-bit coding, the lens is most straightforward to use on mirrorless cameras that accept the M mount through an adapter, or on M bodies used in live-view mode, where focus and framing can be confirmed on screen. As a recent release, documented version differences, finish variants, and production changes are not established.

Optical qualities

Rendering Documented, independent rendering reports for this lens are limited given its recent introduction, so detailed claims about sharpness, bokeh, flare, distortion, and vignetting cannot be stated with confidence. The design intent, signalled by the APO and ASPH labelling together with the eleven-element, seven-group formula and eleven-blade diaphragm, is toward corrected chromatic aberration and smooth out-of-focus rendering, but real-world performance should be confirmed against firsthand testing.