DJ-Optical Unveils Ultra Slim 35mm f/3.5 MC Lens
After exhibiting it at the 2026 China P&E Imaging Show, DJ-Optical has released the Ultra Slim 35mm f/3.5 MC, a compact manual-focus prime lens designed for full-frame Leica M-mount cameras. The new model adopts an unusually thin pancake construction, extending approximately 15mm beyond the camera mount.
The lens is the second model introduced under the DJ-Optical brand, following the NyctaLux 50mm f/1.0, which was released earlier in 2026. Both lenses were developed by an optical designer known as DJ, who reportedly has approximately 30 years of experience in lens manufacturing. However, while the NyctaLux emphasizes a large maximum aperture, the new 35mm model prioritizes reduced dimensions and portability.
The Ultra Slim 35mm f/3.5 MC measures approximately 53mm in diameter and 15mm in length, excluding the mount, and weighs around 140 grams. Its metal housing features a silver finish with gold-colored details, engraved distance markings and a small focusing lever. The design resembles a camera body cap, although it incorporates a conventional optical system and mechanical focusing controls.
Despite its limited dimensions, the optical construction consists of eight elements arranged in five groups, including one extra-low-dispersion element and three high-refractive-index elements. The ED element is intended to reduce chromatic aberrations, while the high-index glass contributes to the compact optical arrangement. Multicoating is also applied to reduce internal reflections and maintain contrast.
The 35mm focal length provides a moderately wide field of view suitable for street photography, travel and general documentary work. Its maximum aperture of f/3.5 is comparatively modest, particularly when compared with larger M-mount lenses offering apertures of f/2 or wider. Consequently, the lens provides less flexibility for low-light photography and shallow-depth-of-field compositions, although the smaller aperture contributes to its compact construction.
Aperture adjustment is available from f/3.5 to f/16 through a continuously rotating, clickless aperture ring. The diaphragm incorporates eight blades, while focusing is entirely manual. Unlike some compact lenses designed primarily for mirrorless cameras, the DJ-Optical model retains mechanical rangefinder coupling, allowing it to operate with compatible Leica M camera bodies.
However, rangefinder coupling is limited to distances between infinity and approximately 0.7 meters, depending on the camera. The lens itself can focus as close as 0.5 meters, but subjects within the 0.5-to-0.7-meter range cannot be focused using the coupled rangefinder mechanism.
The front of the lens incorporates a 25.5mm filter thread, and a matching slim UV filter is included alongside the front and rear lens caps. The filter provides additional protection for the front element without substantially increasing the overall dimensions. The lens is also supplied with a one-year warranty against manufacturing defects in the Japanese market.
The DJ-Optical Ultra Slim 35mm f/3.5 MC went on sale in Japan on October 30, 2026, with a manufacturer’s suggested retail price of ¥110,000, including tax. Some Japanese retailers list the lens at approximately ¥99,000, while international listings place its price at around $520. Availability outside Japan currently depends primarily on specialist retailers and online sellers.
