Pentax SMC D-FA Macro 50mm F2.8 - Review 2022

Pentax's foray into total-frame digital is relatively recent, but it kept a few lenses from the film era in product to lucifer with the digital K-1. One of those is the Pentax SMC D-FA Macro 50mm F2.8 ($299.95), which delivers stiff optical performance, even if its fit and terminate aren't on the same level as more modern lenses. It doesn't have the weather sealing, focus limiter, or internal motor that nosotros're used to seeing on newer glass. But you lot tin't debate with its image quality or its toll, so nosotros recommend it to Pentax shooters searching for a macro lens.

Design

The Macro 50mm is pocket-size and low-cal, coming in at just 2.6 by ii.half-dozen inches (HD) and 9.3 ounces. Its front element is also modest, offer support for the 49mm filter size. The lens does telescope as information technology focuses close, however, which is a departure from modern macros with internal focus designs. The extension makes it feel a bit more fragile than information technology should, but using the included lens hood will protect the optics from whatsoever inadvertent bumps during normal employ.

Pentax SMC D-FA Macro 50mm F2.8 : Sample Image

Electronic aperture control is available, but the lens also includes a physical control ring, which can be used to gear up the discontinuity on older film cameras that don't support electronic control. When used with a modernistic body like the Thou-1 yous can enjoy aligning in third-cease increments, but if y'all do plan on using the ring for control you are more than express. It tin exist gear up at f/ii.8, from f/4 through f/16 in half-stop increments, or at f/22 or f/32.

Autofocus is driven by a screw-drive mechanism, which means the lens is going to make some noise when driven past autofocus. At that place's no focus limiter switch, which means that focus lock tin take some time, especially when trying to movement from infinity to macro distances or vice versa. It takes about a 2nd for the lens to drive focus across its full range. A focus limiter switch, which is used to brand a macro search across only the close or far part of its range, would be welcome, but is absent-minded.

Quick shift focus, which lets you lot brand transmission adjustments while the photographic camera is set to autofocus mode, is supported. The lens also sports a focus clamp, which locks the focus betoken in place, so you won't accidentally change focus either using the photographic camera'south autofocus system or the manual focus ring. It's not something I've seen on any other macro lens in current production, merely is a plus for working from a tripod or re-create stand.

Focus is possible to 5.9 inches, measured from the camera's image sensor, then you lot can get right upwards close to subjects. When focused as shut every bit possible it projects subjects onto the prototype sensor at full life-size, a i:1 magnification ratio. Y'all don't go that with every 50mm macro design—many are limited to 1:2 reproduction.

There's no weather sealing. Pentax does have some other macro in its lineup that is protected from the elements, the D FA 100mm F2.eight Macro WR. It'due south a longer focal length, and a much pricier lens at $550. More troublesome, the D FA 100mm shows strong chromatic aberration, an issue that does non rear its caput with the D-FA Macro 50mm.

Image Quality

I tested the Macro 50mm with the 36MP Chiliad-1. At f/2.8 the lens puts upward strong sharpness results, 2,869 lines per picture summit on the Imatest heart-weighted evaluation. That's amend than the 2,250 lines we like to see at a minimum from the K-one. Image quality is potent through almost of the frame, and while border resolution does drop off (ii,327 lines), it's however reasonably well-baked.

Narrow apertures are typically employed for close-upwardly photography in guild to go a wider depth of field. At f/iv the lens remains potent (2,805 lines) and at f/5.half dozen it hits peak resolution, 3,087 lines, with functioning that is even from edge to edge. The lens maintains high resolution at f/eight (3,081 lines) and f/11 (ii,973 lines).

Related Story See How We Test Digital Cameras

At that place'due south a driblet in score at narrower apertures, due to diffraction. You tin still internet well-baked results at f/16 (ii,794 lines), but the drop at f/22 (2,426 lines) and f/32 (1,995 lines) is strong plenty that you should consider employing focus stacking techniques in your photography when a wide depth of field is required.

There's no distortion of which to speak, so the lens can be used to copy documents or for architectural work without worry. At that place is a bit of corner dimness at wider apertures. The corners lag backside the center past -2.5EV at f/2.8 and past -1.3EV at f/four. At f/v.vi and smaller the deficit is cut to below a negligible -1EV. The Chiliad-1 offers in-photographic camera correction for JPGs, with four levels of adjustment, and Adobe Lightroom tin can be used to burnish dimmed corners if you lot shoot in Raw format.

Conclusions

The Pentax SMC D-FA Macro 50mm F2.8 may not have the fit and stop of a mod lens, merely it does deliver sharp, detailed macro images and it doesn't cost an arm and a leg. We'd love to see the lens updated with a non-telescoping pattern, atmospheric condition protection, an internal focus motor, and a limiter function, to meliorate pair with mod Pentax SLRs. But if yous're more concerned with epitome quality over build, don't count it out, particularly for $300.