Carl Zeiss Biotar 5cm f/1.4 (Uncoupled): Specs, Prices & Comparisons

How it compares

Measured against the 73 other 50mm LTM-mount lenses in the catalogue.

380 g Weight Lighter than 6% of them

f/1.4 Maximum aperture Faster than 86% of them

Specification

Model number(s): Documented serial 888967; reported first-lot range 888901–889000

Focal Length: 50mm

Aperture: 𝑓/1.4

Release Year (from): 1929

Production Year (to): 1929

Diameter: 60 mm

Filter Size: 40.5 mm (E40.5)

Length: 65 mm

Minimum Focus Distance: 2m

Elements in Groups: 6/4

Aperture Blades: 12

Mount: LTM

Material Weight: Brass, 380g

Colors: Black

About this lens

The Carl Zeiss Jena Biotar 5cm f/1.4 profiled here is the original uncoupled M39 version made for the Leica I C Non-Standard. A documented example, serial number 888967, dates from 1929 and retains its black finish and original hood. Its focusing scale begins at 2 metres.

Although the lens uses an M39 thread, it is not a universally interchangeable 28.8mm-register LTM lens. Leica I C Non-Standard cameras did not yet share a fixed flange-to-film distance, so lenses had to be individually matched to a particular camera body. This Biotar also has no mechanical rangefinder cam.

The optics use the six-element, four-group 50mm f/1.4 calculation completed on 6 May 1929 for the full 24×36mm format. Historical research estimates approximately 100 Leica-fitted examples from this calculation, although that total should not be attributed exclusively to the uncoupled barrel. A neighbouring first-lot example, serial number 888971, is reported with twelve aperture blades and an f/16 minimum aperture; those values are used here as the best available first-lot specification.