Leica Summilux-R 50mm f/1.4

It is two in the morning in a hotel bar and the only light is a sconce behind the bottles. The Leicaflex shooter next to you racks the Summilux-R to f/1.4 and gets the shot anyway. That is the whole pitch for this lens. It was built for the kind of evening where you have already given up on a meter reading and you are working on instinct and one stop of headroom you did not think you had.

This is the early R-mount fast fifty, the 55mm filter version that ran from the mid-1970s, and it glows wide open. There is a veil of spherical aberration at f/1.4 that softens skin and lifts the shadows into a low haze, and people either chase that look or hate it. Stop down to f/2.8 and the haze burns off and the thing gets properly sharp. If you want clinical bite at full aperture this is not the barrel for it. Leica did eventually redesign the lens, growing it to a larger 60mm front and a revised formula that tightened up the wide-open performance, but that is a separate model with a different filter thread. The one in front of you, the 55mm, is the dreamy one, and that is the reason to own it.

Rendering is the reason these stay expensive. Out-of-focus highlights come back round and quiet, with none of the nervous edge you see on cheaper fast fifties, and the falloff from the focus plane is gradual rather than abrupt. Color is warm and slightly muted, less clinical than the contemporary Planar-school Japanese glass that everyone cross-shops it against. The honest weakness is flare. Point it at a hard backlight and contrast collapses into a milky wash, because the coatings are old and the front element is large and exposed. Use the hood. Always use the hood.

Who buys one now. Portrait shooters who scan their film and want a face that looks alive rather than measured, and a small group of cinematographers who adapt R glass to digital cine bodies for exactly that rounded falloff. The cross-shop is usually a Contax Zeiss Planar 50mm f/1.4, or the fast fifties from Canon FD and Minolta if you want a similar speed at a fraction of the money. People who want the opposite philosophy, sharp and corrected at full bore, go looking at something like the aspherical Nikon Noct-Nikkor, but that is a 58mm f/1.2 chasing a completely different render. The Leica wins on character and loses on price and on being lockable to a body Leica stopped supporting. There is no electronic anything and no shutter in the lens, just an aperture ring and a focus helicoid that will outlive you.

The practical note. Wide open in that bar, your camera's meter is reading off a near-black scene and will lie to you, biasing the exposure way up. This is where I meter the actual highlight I care about, the sconce or the lit face, with Zone Light Meter and place it on the zone I want rather than trusting the body's averaged read. The 55mm filter thread matters too if you screw on an ND to hold f/1.4 in daylight; factor that filter into the reading and you keep the glow without blowing the frame.