HD Pentax-D FA* 50mm F1.4 SDM AW Review

The HD Pentax-D FA* 50mm F1.4 SDM AW ($1,199.95) is a highly anticipated lens among Pentax system owners.

It's a modern, full-frame, prime lens with strong optical quality, weather sealing, and an internal focus motor.

It's a very strong performer, much more so than the aged FA 50mm F1.4, but also a lot more expensive and bulkier.

It's the best 50mm F1.4 you can get for the K-1, earning our Editors' Choice recommendation, though it's a shame more third-party alternatives aren't available in K-mount.

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Another Big 50mm

There was a time when 50mm f/1.4 lenses tended to be pretty small.

But as image sensors have become laden with denser pixel counts, lens designs have become more complex in order to deliver exceptional image quality when shot wide open.

The first crazy-big 50mm we saw was the premium, manual focus Zeiss Otus 1.4/55, but it was soon joined by the autofocusing Sigma 50mm F1.4 DG HSM Art.

Unfortunately, the Sigma lens isn't sold for Pentax K cameras, as it is much more affordable.

The FA* 50mm F1.4 SDM AW owes something to the chunky 50mm lenses that have come before it.

It measures 4.2 by 3.2 inches (HW), weighs just over 2 pounds, and supports 72mm front filters.

The barrel is black, with a green accent ring at the base and a gold one toward the front.

A reversible lens hood, front and rear caps, and a carrying case are included.

The only control switch of note is on the side, an AF/MF toggle to the focus mode.

The manual focus ring occupies a good portion of the barrel and is covered in textured rubber.

It's comfortable to grip and turn, even if you're wearing gloves.

There is a cut-out window at the top to show the set focus distance—the scale is in feet and meters.

The lens doesn't include a depth of field scale, which is typical of modern designs.

The AW designation indicates the lens is protected from dust and moisture, so you can use it in any sort of inclement conditions when paired with a weather-sealed SLR.

Almost every K-mount camera from Pentax offers weather protection.

Close focus is available to 15.6 inches (39.2cm), pretty typical for a 50mm f/1.4.

It's not macro territory—subject magnification is 1:5.6 life-size at the closest focus distance.

Despite its age and lack of weather sealing, we like the D-FA Macro 50mm F2.8.

We also like the newer HD DA 35mm F2.8 Macro Limited, which is designed for APS-C cameras, but did a decent job on the full-frame K-1, showing a minimal vignette.

Sharp Wide Open

One of the results of the move to larger 50mm designs is better performance at f/1.4.

The HD Pentax-D is not an exception.

I tested it with the 36MP K-1 Mark II and Imatest software.

At f/1.4 the combination nets 2,682 lines on a center-weighted sharpness evaluation.

That's a bit better than the 2,250 lines we want to see at a minimum from a 36MP image sensor.

Edges are just a little soft, showing 2,000 lines, but they'll be blurred out by shallow depth of field for the vast majority of f/1.4 images.

At f/2 the resolution jumps to 2,739 lines, although edge quality is about the same as at f/1.4.

The periphery improves at f/2.8 (2,176 lines), along with the average (2,878 lines).

At f/2.8 we see the resolution climb toward the highest the lens manages, 2,991 lines, with edges that show a strong 2,421 lines.

Absolute peak resolution is at f/5.6 (3,024 lines) and f/8 (3,028 lines), and edges show about 2,750 and 2,975 lines at those settings, respectively.

You'll get crisp results from center to edge when working at these f-stops.

Performance at f/11 is almost as good—2,923 lines.

There's a slight drop in resolution at the minimum f/16 setting, but at 2,743 lines you'll still get good results there.

We don't see any noticeable barrel distortion, just about 0.2-percent, which is inconsequential.

There is a bit of a vignette.

If you shoot in Raw format, or disable in-camera vignette control, you'll see a -2.6EV drop at the corners at f/1.4.

The deficit drops to -1.5EV at f/2, and it's a barely perceptible -0.7EV at f/4 and narrower settings.

In-camera correction cuts the drop in corner illumination to -0.8EV at f/1.4, which isn't anything to fret over.

A High-Class Lens at a High-Class Price

Pentax owners finally have a 50mm lens that can keep up with the 36MP K-1 and K-1 Mark II in the form of the HD Pentax-D FA* 50mm F1.4 SDM AW.

It's sharp, even at f/1.4, free of distortion, weather sealed, and while there's a bit of a vignette at wider f-stops, it's nothing you can't correct for with software.

But it's also priced around $1,200.

It's not the most expensive lens of this type we've seen—the 50mm F1.4 Sony sells for its full-frame mirrorless system is priced at $1,500, for example.

But it is a premium option compared with the Sigma 50mm F1.4 DG HSM Art, which is priced under $1,000 and regularly sells for a bit less.

Sigma's alternative is not available in the Pentax K-mount, however.

For these reasons, we're naming the FA* 50mm our Editors' Choice.

Pentax owners are paying a slight premium, no doubt influenced by a lack of viable third-party alternatives.

There are more affordable options to consider.

We don't recommend buying the older FA 50mm F1.4 lens—it's soft, not protected from weather, and noisy to focus.

But if you're willing to use a lens with a slightly wider angle of view, don't forget about the FA 43mm f/1.9 Limited, which delivers very strong optical performance in a smaller, more affordable package—but it doesn't have weather sealing.

You may also want to think about the Sigma 35mm F1.4 DG HSM Art, although if you're like me, a 35mm is no substitute for a 50mm.