Leica Summicron-M 35mm f/2 (v4, King of Bokeh)

It picked up an unusual nickname: King of Bokeh. The fourth version of the Summicron-M 35, made from 1979 to 1996, is the one people hunt for on the used market, and they are not paying for resolution charts. They are paying for what happens behind the plane of focus. Out-of-focus highlights render as soft, rounded shapes that mostly avoid the hard outlining and onion-ring texture seen in some later designs, and the transition from sharp to soft is gentle in a way the aspherical successors deliberately walked away from.

The optics are a classic double-Gauss arrangement with no aspherical element, which is exactly the point. Leica's later 35 Summicron ASPH cleaned up the edges, knocked down coma, and raised wide-open contrast. It also flattened that creamy falloff. The v4 keeps a touch of field curvature and slightly lower micro-contrast at f/2, and that softer behavior is precisely what makes the rendering look organic rather than computed. Stop down to f/4 and it sharpens up across the frame and tightens its corners. Wide open it is sharp in the center, honest about the edges, and it draws faces with presence instead of a hard machined edge.

This is a street and reportage lens first. The 35mm focal length on a Leica M is the documentary standard, close enough to fill a frame with a person, wide enough to keep the room around them. The small barrel and the 39mm filter thread keep it compact and unobtrusive, and the rendering flatters black and white skin tones and city light. Photographers who work close and fast tend to reach for this rather than the surgically corrected modern glass.

The honest weakness is flare. Point it into a bright backlight or a streetlight at night and contrast drops, veiling haze creeps in, and you can catch ghosting. The older non-ASPH design flares more readily than the later ASPH optics, so a vented hood earns its place. If you want clean sun stars and locked contrast against the light, the ASPH is the better tool. The v4 is bought for how it draws, not for torture-test resistance.

On price, the v4 trades well above what its age and simple design would suggest, and people cross-shop it against the 35 Summicron ASPH and the faster 35 Summilux. The Summilux gives you f/1.4 and more drama; the ASPH gives you corrected, even rendering across the frame. The v4 is the one you choose when you want that older bokeh signature specifically, and clean copies command a premium that has held for years.

One metering note. At f/2 in dim interiors you are often working near the bottom of the exposure range, and a rangefinder gives you no through-the-lens reading, so set Zone Light Meter to meter for the shadows you care about and let the highlights fall where they land. If you screw a strong ND or a grad onto that 39mm thread for daylight wide-open work, dial the filter factor in first so the indicated exposure already accounts for it before you trip the shutter.