Astrhori 24mm f/6.3 Full-frame Large Aperture

The Astrhori 24mm f/6.3 Full-frame Large Aperture is a M-mount lens for Leica rangefinder cameras. Leica price index ↗

Reference maintained by Thomas Boots

Focal Length: 24mm

Aperture: 𝑓/6.3

Release Year (from): 2018

Diameter: 27 mm

Length: 37 mm

Minimum Focus Distance: 0.24m

Elements in Groups: 5/5

Mount: M

Material Weight: Metal, 82g

Colors: Black, Silver

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AstrHori 24mm f/6.3 Full-frame Large Aperture

Unusual among Leica M-mount optics, this AstrHori is a fixed-aperture pancake with no diaphragm at all: the lens works at a single value of f/6.3 and has no adjustable iris, so the conventional notion of aperture blades does not apply. It is designed around hyperfocal, zone-focus shooting rather than precise focusing, which suits the deep depth of field that a 24mm wide angle delivers at a small working aperture [1]. AstrHori is a modern Chinese lens manufacturer that, according to industry coverage, was previously known as Rockstar, and the 24mm f/6.3 was among the first M-mount products it brought to market, sold at a low introductory price of around 299 US dollars [2].

The optical formula uses five elements in five groups, with two aspherical elements that the manufacturer says are included to keep distortion very low [1]. The lens has an all-metal barrel and multi-coated glass, and instead of a screw-on front thread it uses a built-in slot system that accepts compatible filters such as UV, ND and CPL [1]. It is a true pancake, very compact and light, and mounts directly on Leica M-mount bodies including film and digital models such as the M6, M8, M9, M10, M11, MP and M240, with adapter rings allowing use on other mirrorless mounts [1]. Although AstrHori's own marketing describes the lens as offering rangefinder focus, it is not mechanically coupled to a Leica rangefinder, so focusing in practice relies on the distance and depth-of-field scale rather than the camera's coincident-image patch.

The lens is offered in black and silver finishes, and B&H assigns the silver Leica M version the product code A10S [3]. There are no widely documented optical or coating revisions; the design has been sold essentially unchanged since its introduction.

Optical qualities

Rendering Documented, independent technical analysis of this lens is limited, so claims about its rendering should be treated cautiously. The manufacturer states that the two aspherical elements give the lens very low distortion and good resolution, and that the multi-coating helps image quality [1]. Because the lens operates only at f/6.3 on a 24mm focal length, it produces extensive depth of field, which is the basis of its intended hyperfocal, fixed-focus use rather than selective-focus or shallow depth-of-field work [1].

History

Development and Launch AstrHori introduced the 24mm f/6.3 as part of its first wave of Leica M-mount lenses, which became available through mainstream retail channels including Amazon [2]. The maker positioned it as an inexpensive, compact wide-angle aimed at enthusiasts and newcomers to manual-focus shooting, emphasizing portability and ease of use over optical ambition [1].

Special editions No major factory special editions or military, export, or regional variants of this lens are documented; it is sold as a standard product in black and silver finishes [1][3].

Collector Notes Buyers should be aware that this is a contemporary, low-cost lens rather than a vintage collectible, and that its single fixed f/6.3 aperture and lack of an iris are inherent to the design rather than faults. The maker's reference to rangefinder focus does not mean the lens is rangefinder coupled, so it should not be expected to drive a Leica focusing patch. Some early listings circulated differing physical figures for weight and length, so prospective buyers should rely on the confirmed specifications rather than promotional copy. When buying used, verify which finish and mount are supplied and whether any adapter ring is included, since adapters for non-M cameras are normally sold separately [1][2].