Nikon Nikkor 24mm f/2.8 AI

Put this next to a Canon FD 24mm f/2.8 from the same years and the differences are smaller than the brand loyalists pretend. Both are compact retrofocus 24s, both go soft and a little hazy in the corners wide open, both tighten up beautifully by f/5.6. What you are really choosing is the system around the glass. If your bodies say Nikon F on the front, this is the wide you reach for, and it is one of the easiest manual focus 24s to live with that Nikon ever sold.

Wide open at f/2.8 the center is already crisp and the contrast is honest, but the edges trail off into low-contrast smear and a touch of field curvature, so a flat brick wall will never look flat across the whole frame at full aperture. Stop to f/5.6 and the corners snap into line; by f/8 to f/11 the frame is uniformly sharp and that is where most people who own one actually shoot it. Distortion is the usual retrofocus barrel, mild and well-behaved, easy to ignore for streets and reportage and only a nuisance if you put a horizon dead at the edge. Color runs cool and neutral, the way most Nikkors of this period read on slide film, and flare resistance is decent for late-1970s multicoating, though a low sun in the corner will still throw a veil. The 24mm f/2.8 has carried Nikon's CRC floating-element design since its earliest versions, and this AI keeps it, nine elements in nine groups, so close-focus sharpness holds up well down to its 0.3m minimum. The AI and AI-S share the same optics. Do not pay a premium chasing an upgrade that is not there.

Who uses it: documentary and travel shooters who want one small, tough, all-metal wide that takes the same cheap 52mm filters as every other classic Nikkor in the bag. The angle of view is the photojournalist's standard, wide enough to set a scene, tight enough that you can put a person near the edge of the frame without the stretch you get from a 20mm. It is a street and environmental-portrait lens more than a landscape specialist, although stopped down it does landscapes fine.

The honest weakness, beyond those soft wide-open corners, is the way it handles bright point sources. Shoot streetlights or stars at f/2.8 and they tend to show some coma, little wings pulling toward the edges, so this is not the astro lens some people hope a fast-ish 24 will be. Stopping down cleans it up but you give back the speed you bought it for.

Today it sits in the affordable-classic bracket, cheaper than its own AI-S successor and a fraction of any modern 24, which is exactly why people keep buying it. The 52mm thread makes it a natural for screw-in grads and polarizers on landscape outings, and since it has no shutter of its own, you meter it like any other manual lens. In Zone Light Meter, frame your scene, meter off the zone you want to anchor, set the aperture by hand and let the body do the rest. Cross-shopped against the Canon FD 24 and the contemporary 24mm primes from Olympus and Pentax, it holds its own optically and gives you the deepest system to grow into.