Canon EF 50mm f/2.5 Compact Macro

One of the sharpest, flattest-field fifties Canon ever built, and for most of its life it sold for short money. The "Compact Macro" name buries what it actually is. This is a flat-field 50mm that holds a true plane of focus across the frame, which makes it a copy-stand and document lens as much as a portrait one. People bought it cheap and walked away with glass that outresolved primes costing several times more.

The catch sits right in the spec sheet. On its own it only focuses to half life size, 1:2, not the 1:1 the word macro implies. Canon sold a dedicated Life Size Converter, a small optical adapter, to push it to 1:1, and without it you are stuck at half. For copying slides or filling the frame with a wedding ring, half is short. That is the honest weakness, and it is why a lot of shooters reached past it for the EF 100mm f/2.8 Macro, which goes to 1:1 native and gives more working distance for skittish subjects. It is also worth saying that the EF 50mm f/1.8 nifty fifty was cheaper still, so the value pitch here is sharpness and flat field, not rock-bottom price.

Optically it runs 9 elements in 8 groups with a floating element group that shifts to hold correction across the focus range, tuned for flat-field close work rather than the soft glow most fast fifties lean on. Wide open at f/2.5 it is already crisp, with a little veiling at the edges that closes by f/4. Contrast is high. Color is neutral and runs slightly cool. It is conventionally multicoated, and flare control is good in normal use. Bokeh is the compromise. Flat-field correction trades smooth out-of-focus rendering for sharpness, so backgrounds can get nervous and busy at portrait distances. This is not the lens for creamy separation. It is the lens for reading the texture of a fern or the weave of a fabric.

Who actually shoots it: product and flat-art copy people, focus-stack hobbyists, and budget shooters who want one tack-sharp fifty that also does close work. On a crop body it became an 80mm equivalent and turned into a sleeper portrait-detail lens despite the busy bokeh. It stayed in production from 1987 all the way to 2018 with no optical revision, so the formula clearly held up. Used copies are everywhere and cheap, and the cross-shop is always the same: this for sharpness and price, the 100mm if you need true 1:1.

One field note. Rack it toward minimum focus and the extension eats light. At half life size you lose roughly a stop, climbing toward about a stop and a half as you near 1:1 with the Life Size Converter, which itself drops the maximum aperture from f/2.5 to f/3.5, and nothing in TTL warns you if you are on flash or an external meter. Zone Light Meter computes the bellows (extension) factor for you, so you can dial the real working aperture at close distance instead of guessing and bracketing. On a tripod copy setup that one correction keeps a negative from coming out thin.