Minolta MD 24mm f/2.8

Eleven millimetres. That is how much Minolta took off the length of its 24mm when the plain MD version went on sale in Japan in June 1981, and it managed it without dropping the floating element that made the older lens worth owning. The New MD range arrived with the X-700 that summer. It dropped the Rokkor name from most of the line, which is why collectors call these plain MD lenses. Each one has a minimum-aperture lock for program and shutter-priority modes, and a groove at the front for the clip-in hoods that came with the range.

Rokkor Files singles out the 24mm as one lens Minolta changed significantly in this third generation. The nine elements in seven groups went down to eight elements in eight groups, and the filter thread went from 55 mm to 49 mm, the same size the MD 28mm f/2.8 already used. Wikipedia's SR lens table gives the new barrel as 64 by 39 mm, against 65 by 50 for the nine-element lens. So the diameter hardly changed and nearly a centimetre came off the length. Minolta's own data lists 200 g, a closest focus of 0.25 m and a launch price of 39,000 yen.

The floating element matters more on a 24 than on most lenses. A group that moves at its own rate as you focus keeps the correction intact up close, and wide-angle pictures often live or die on a foreground rock, a doorframe or a table edge half a metre from the lens. Eight elements in eight groups also means nothing inside is cemented together. On a lens now more than forty years old, that leaves one less thing to go cloudy. The Rokkor Files author, who rates the older formula among the sharpest lenses he has used, says plainly that he hasn't shot the new one himself. Owners told him it holds up, which is what he expected once the floating group stayed in.

Its limit is f/2.8. That was normal for a 24 in 1981, but handheld interiors on slow film will push you to the edge of your shutter speeds, and the lens gives you no faster aperture to fall back on. Stacking filters on a wide lens with a slim front can also start to darken the corners, so use one good filter rather than a pile. Buy it the way you would buy any used wide-angle: from a seller who takes returns, then shoot a flat subject at f/8 and look at all four corners before the return window closes.

Landscape and architecture are the obvious work. On an X-700 it is also small enough to stay mounted all day for street photography. Black-and-white skies usually want a yellow or orange filter, and at 49 mm those cost very little. Zone Light Meter reads the scene through the phone, which never sees that glass, so choose the filter from the app's filter list and its factor goes into every reading.

Minolta's 24mm lenses are not hard to find used. The real choice is against the lens it replaced, the nine-element MD W.Rokkor with its 55 mm thread and longer barrel. If your 28 and 50 already take 49 mm filters and you want a wide lens you'll actually leave on the camera, the plain MD is the one to get.