Voigtländer Nokton 40mm f/1.4

Voigtländer Nokton 40mm f/1.4

Part of Cosina's Voigtländer Classic line, the Nokton 40mm f/1.4 stands out for packing an f/1.4 maximum aperture into an unusually small barrel, making it one of the most compact fast normal lenses available in Leica M mount [1]. The 40mm focal length is uncommon among current rangefinder lenses and revives a length long associated with the Leica CL and Minolta CLE, while the lens itself draws clear visual and structural inspiration from the compact Leica 35mm f/1.4 Summilux of the same era, including a similar aperture ring layout [1]. Its low cost relative to other fast M-mount options has made it a popular entry point for photographers who want a small, fast normal lens [1].

The optical formula uses seven elements in six groups in an all-spherical design, and the diaphragm is built from ten straight blades [1]. Because the blades are straight, out-of-focus highlights take on a decagonal shape once the lens is stopped down past wide open [1]. The barrel is rangefinder-coupled, focuses to 0.7 m, and accepts 43 mm filters, and reviewers describe the build quality and handling as solid for the class [1]. One handling point is specific to the 40mm focal length: the lens does not bring up dedicated framelines on most Leica M bodies, instead summoning the 50mm frame on cameras such as the M6 TTL, so users typically compose with the 50mm lines, modify the lens to trigger the 35mm frame, or use an external 40mm brightline finder [2].

The lens has been produced in two coating versions, a multi-coated (MC) variant and a single-coated (SC) variant, the latter intended to give a more vintage, lower-contrast rendering with more pronounced glow and flare [1][2]. It should not be confused with the later and optically more complex Voigtländer 40mm f/1.2 Nokton Aspherical, which is a separate, faster design [1]. Both 40mm f/1.4 versions are black and share the same compact dimensions.

Optical qualities

Rendering The lens behaves differently wide open than when stopped down. At f/1.4 it shows noticeable spherical aberration and glow with softer contrast, a character some users seek out, while from about f/2.0 sharpness and contrast improve markedly and the rendering becomes cleaner [1]. The drawing is often compared to simpler fast lenses where the wide-open look is a deliberate trait rather than a defect [1].

Sharpness Wide-open central performance is modest and affected by aberration and field curvature toward the corners; stopping down to f/2.0 and beyond brings sharpness up where it matters [1]. The lens exhibits focus shift, so the plane of best focus moves as it is stopped down, something to be aware of on high-resolution bodies [1].

Bokeh and transitions Out-of-focus rendering is smoother once stopped down to around f/2.0, while wide open the residual spherical aberration adds glow to highlights [1]. Because the design is all-spherical, defocused highlights are free of onion-ring texture, though the straight blades render them as decagons when stopped down [1].

Flare resistance The multi-coated version is highly resistant to flare and artefacts even in difficult backlight, consistent with most modern Voigtländer optics; the single-coated version is expected to behave very differently and flare more readily by design [1].

Distortion and vignetting Distortion is present but moderate and correctable with a profile [1]. Vignetting is one of the lens's weaker points, with visible light falloff wide open [1].

Collector and user notes A frequently cited advantage of the 40mm over Voigtländer's 35mm f/1.4 Classic is the absence of strong barrel distortion and focus shift problems of the kind seen on that wider lens [2].

History

Development and Launch The Nokton 40mm f/1.4 belongs to Cosina's Voigtländer Classic series of compact, affordable rangefinder lenses, positioned as a small fast normal for the Leica M and CL/CLE-style 40mm tradition [1]. It has remained in production as a current catalogue item, offered alongside the rest of the Voigtländer M-mount range [1].

Production Evolution The principal documented variation is the coating: the lens has been sold in multi-coated (MC) and single-coated (SC) forms, with the SC version aimed at a more classic, lower-contrast look [1][2]. The two versions otherwise share the same optical layout and compact dimensions [1].

Special editions No major factory special editions of the 40mm f/1.4 are widely documented beyond the MC and SC coating variants. Voigtländer separately produced now-uncommon 40mm brightline viewfinders to suit the focal length [2].

Collector Notes The most common point of confusion is the missing native 40mm frameline on most M bodies, which brings up the 50mm frame instead; some owners modify the lens cam to trigger the 35mm frame, while others use an accessory 40mm finder [2]. Buyers should also distinguish the f/1.4 Nokton Classic from the later, larger 40mm f/1.2 Nokton Aspherical, and confirm whether a given example is the MC or SC coating, since the two render differently [1]. Independent measurements of weight and length vary slightly from quoted figures, which is normal for production tolerances and sample measurement; defer to the verified specifications for catalogue values [1].

Sources

• [1] Phillip Reeve (BastianK). Review: Voigtländer VM 40mm 1.4 Nokton MC. https://phillipreeve.net/blog/vm_40mm_1-4_nokton_mc/
• [2] Johnny Martyr. Voigtländer 40mm 1.4 Nokton Classic MC Review. https://johnnymartyr.wordpress.com/2019/10/02/voigtlander-40mm-1-4-nokton-classic-mc-review/