Voigtländer Septon 40mm f/2 Aspherical

The Voigtländer Septon 40mm f/2 Aspherical is a compact manual focus standard lens for full frame mirrorless cameras, made for Sony E and Nikon Z. Cosina describes it as a pancake-style lens, and its main selling point is how little space it takes on the camera.

Optical design

The lens has 7 elements in 6 groups. Cosina calls the layout a seven-element Orthometer design and says it reaches an aperture of f/2 with an angle of view of 57.3 degrees, which suits both standard and mild wide-angle use. The aperture has 10 blades and closes down to f/22.

Focusing and handling

Focusing is manual through an all-metal helicoid. The closest focus distance is 0.3 m with a maximum reproduction ratio of 1:5.3, which is close for a 40mm lens. Electronic contacts record Exif data and enable focus magnification, and the distance encoder supports in-body stabilization on bodies that have it. There is no autofocus and no stabilizer in the lens.

Build and size

The total length from the mount is 30 mm on Sony E and 32 mm on Nikon Z. The Sony E version weighs 165 g and measures 61.7 x 30.0 mm, and the Nikon Z version weighs 205 g and measures 68.3 x 32.0 mm. The filter thread is 52 mm on both. A dome-shaped metal screw-in hood is included, and its outer thread of 52 mm lets the same front cap fit with or without the hood.

Where it fits

Among small standard lenses with autofocus, the Nikon Nikkor Z 40mm F2, the Sony FE 40mm F2.5 G and the Viltrox AF 40mm F2.5 are the obvious comparisons. For manual lenses from Voigtländer there is the VM 40mm F2.8 Heliar on Sony E, and the much faster but larger Nokton 40mm f/1.2 on Nikon Z.

Pros and cons

Pros

• Only 30 to 32 mm long and 165 to 205 g
• f/2 maximum aperture with 10 aperture blades
• Close focus at 0.3 m
• Metal hood included, small 52 mm filters

Cons

• Manual focus only
• No stabilization in the lens
• f/2 is slower than the f/1.2 Nokton alternatives
• The Nikon Z version is 40 g heavier and 2 mm longer than the Sony E version

Verdict

The Septon 40mm f/2 is for photographers who want a small, light standard lens that stays on the camera all day. It trades autofocus and speed for compactness, and for that kind of use the trade can make sense.