Carl Zeiss Hologon T* 16mm f/8 G

Mount it on a Contax G2 and you almost lose the lens against the body. It is a stub of glass, barely deeper than a body cap, and people who have only seen the photos are always surprised by how little there is to hold. That is the first trick of the Hologon. The second one shows up on the contact sheet: 16mm of coverage, about 107 degrees on the diagonal, and straight lines that stay straight all the way into the corners.

The Hologon name goes back to Erhard Glatzel's symmetric ultrawide design for Zeiss, the formula that first appeared on the Hologon Ultrawide bodies in the 1960s. The Contax G version is a reworking of that idea for the G rangefinder system. It is a symmetric, quasi-concentric layout that draws a rectilinear world, and the symmetry is what cancels the odd-order errors: distortion, coma, lateral color. That is the real reason the lines come out ruler straight, not any retrofocus trickery. There is no autofocus and effectively no focusing at all. At f/8 the depth of field swallows everything from a meter or so out to infinity, so you frame, you trip the shutter, and the lens does the rest.

What it renders is the appeal. Center sharpness is excellent and holds remarkably well toward the edges, which is the payoff of a symmetric design with no front-to-back asymmetry throwing in transverse aberrations. Contrast is high in the classic T* way. Bokeh is a non topic here; at f/8 to f/16 with this much coverage, almost nothing is out of focus, so you do not buy this lens for subject separation. You buy it for architecture, tight interiors, streetscapes where you want to stand inside the scene rather than across the road from it.

The honest limitation is light, two ways. The maximum aperture is f/8, so this is a daylight or tripod lens, not something for a dim bar. And the Hologon falls off hard at the edges the way every extreme symmetric wide does. Its chief rays hit the film at steep oblique angles, so the cos-to-the-fourth law works against you and the corners go dark. Zeiss shipped it with a center graduated ND filter that is darker in the middle and clear at the rim, which evens the frame out but costs you roughly a stop overall. Factor that loss into your reading. The filter compensation in Zone Light Meter handles it cleanly, so you can meter the scene normally and dial the filter factor rather than guessing in your head.

These trade at serious money now. They were rare new and they are rarer today, and prices reflect a small production run for a discontinued system. The honest cross shop is the Voigtlander 15mm Heliar in screw or M mount, which costs a fraction and gives you a stop or two more speed, at the price of more edge falloff and less of that Zeiss geometry. People still chase the Hologon because nothing else this small draws a 16mm frame this cleanly. It does one thing, it does it without compromise, and that single-mindedness is the whole reason it has a following.