Ultra-compact Voigtlander Heliar pancake at 40mm in L39 screw mount, aspherical optics at just 85g.
The Voigtlander 40mm f/2.8 Asph Heliar L39 is a standard prime for the Leica Thread Mount (LTM/M39 screw mount) — the 'L39' in the name explicitly indicates the screw mount version, distinct from the VM bayonet sibling (id 2623). Aspherical element. Leica Thread Mount.
f/2.8 maximum aperture. 40mm focal length (full-frame near-normal prime). Aspherical element. LTM (Leica Thread Mount, M39 screw). Manual focus. Leica Thread Mount.
The Heliar 40mm L39 uses the M39 screw thread — not the Leica M bayonet of the VM version (id 2623). The Heliar is Voigtlander's heritage prime designation. Adapts to Leica M and modern mirrorless via M39 adapter. Near-normal 40mm perspective.
On the used market the Voigtlander Heliar 40mm f/2.8 L39 is a compact LTM prime. Condition checks: front element, LTM screw thread, focus ring. Leica Thread Mount (M39/LTM) — not the VM bayonet.