Olympus E.Zuiko 42mm f/2.8 (35 RC fixed)

Olympus built this lens for a pocket. The 35 RC arrived in 1970 as the smallest rangefinder Olympus could make that still kept a real coupled focusing patch and a proper meter readout in the finder, and the 42mm f/2.8 was the optic that had to fit inside that shrunken body. Olympus was already a house obsessed with miniaturization, with the half-frame Pen behind it and the compact OM SLRs soon to follow, so the RC's lens gives up almost nothing while taking up almost no space. It is permanently mounted and leaf-shuttered, built for a camera you could forget was riding in your coat.

Optically it is a five-element, four-group design. The "E" in E.Zuiko marks five elements, and that fifth one matters: this is not a simple Tessar. A four-element Tessar is enough at 45mm or 50mm at f/2.8, but Olympus needed more glass to hold the corners and the contrast at 42mm, so they added an element. The payoff shows on the negative. Stopped down to f/5.6 or f/8 the center is crisp and the contrast runs high in a slightly old-fashioned way, deep blacks and no haze. Wide open at f/2.8 the edges soften and the extreme corners go a little smeary, which on a 42mm normal you rarely catch because your subject is usually mid-frame anyway. Color is neutral leaning warm. Flare is better controlled than the single-coating era would suggest, though aim it at a streetlight after dark and a veiling glow creeps in.

The 42mm length is the quiet genius of the thing. It sits between the 35mm reportage default and the 50mm normal, close enough to how the eye frames a scene that compositions feel effortless. Backgrounds are smooth but not especially distinctive; some shooters like the falloff wide open, others find it plain, and either read is fair. Nobody chases this lens for creamy portrait separation. They keep it because the whole camera disappears and the frames come back sharp.

The honest weakness is the f/2.8 ceiling. This is not a low-light lens. Indoors or after dark you are leaning on slow shutter speeds, and the RC's meter caps where it caps. If you want a fast normal in a compact body, the Canon QL17's 40mm f/1.7 or the Olympus 35 SP's own 42mm f/1.7 are what people cross-shop, and both pull noticeably more light.

One practical note that earns its keep. The leaf shutter syncs flash at every speed, the full 1/15 to 1/500 range, which is the real reason to hold onto this body for daylight fill. A focal-plane SLR strands you around 1/60 with flash; the RC does not. Meter the ambient scene in Zone Light Meter, set your aperture for the flash, then drop the background a stop or two on shutter speed alone without ever losing sync. Today the 35 RC is a cheap, almost cult carry camera, often working for the price of a few rolls. People still hunt it down because that 42mm Zuiko punches well above what the camera costs, and because nothing else this small focuses with a real rangefinder patch.