Minolta MC Rokkor-PF 55mm f/1.7

It keeps falling out of thrift-store SR-T 101 kits, still screwed to the body, the focus ring still buttery after fifty years. Minolta sold the MC Rokkor-PF 55mm f/1.7 as the cheap standard option from 1966 to 1973, the budget sibling to the f/1.4, and it outlived its own pedigree because it is quietly very good and people keep finding it cheap.

The PF in the name is Minolta's own shorthand for the construction. The first letter encodes the number of groups, P for penta, so five groups, and the second letter encodes the number of elements, F for six. Six elements in five groups, a classic double-Gauss, the workhorse formula behind almost every fast normal of the era. Wide open at f/1.7 it is soft with lowered contrast and a faint glow that lifts off skin tones rather than sitting hard on them. Stop down to f/4 and it snaps into proper sharpness across most of the frame, holding well into the corners by f/5.6. Minolta's coatings of this period run warm, so colors lean amber and the whole image carries a slightly vintage cast.

The out-of-focus rendering is the reason it gets kept. Backgrounds dissolve smoothly without the nervous, busy edges cheaper fifties throw at you. Stopped down past f/2.8 the specular highlights take on a faceted shape from the aperture blades, but wide open the discs stay round and clean. Focus falloff from the plane is gradual rather than abrupt, which is why budget portrait shooters keep reaching for it over more clinical modern glass.

It lives now as a beginner's first fast lens and a cheap entry to manual glass on a digital body. Adapt it to a Sony or Fuji mirrorless and you get that warm, low-contrast wide-open look for the price of a couple of rolls of film, which is why it gets cross-shopped against the Canon FD 50mm f/1.8 and the Pentax Super-Takumar 55mm. The Minolta usually wins on color warmth and loses on flare control. That is the honest weakness. Point it near a light source and veiling flare washes the contrast right out, badly so with no hood. It has no flare-resistant modern multicoating and it shows.

The f/1.7 maximum is the whole point of owning it. This is a lens you buy to shoot indoors, at dusk, in a dim bar, wherever the light is short. Meter wide open in those conditions and let Zone Light Meter place your shadows where you want them, because at f/1.7 your depth of field is thin and only one plane comes up sharp, so the exposure decision and the focus decision land together. The 55mm filter thread takes common rings, so ND and polarizers are easy to source if you carry it out into daylight instead.