Leica's compact vintage 90mm — 3-element Elmar f/4 in chrome, a collapsible telephoto.
The Leica Elmar 90mm f/4 (3 Element, Chrome) is a vintage collapsible telephoto for M-mount — the simplest and most compact 90mm in the M system. The 3-element design predates more complex formulas.
Optically basic by modern standards — the 3-element formula is simpler than later 4+ element designs. Adequate from f/5.6. The f/4 aperture is slow but the collapsible design makes it the smallest M 90mm ever made.
Leica M mount. Chrome finish. 3-element optical design. Collapsible on some versions — retracting into the body. The most compact M 90mm. E39 filter thread.
Available used at budget to mid-range prices — the simplest and cheapest Leica M 90mm. The 3-element optics are limiting. For collectors and budget M telephoto needs. Check for haze and smooth operation.