HD Pentax-D FA 150-450mm F4.5-5.6

Conclusion

The HD Pentax-D FA 150-450mm F4.5-5.6 ED DC AW is a unique and currently unrivaled lens in the K-mount landscape with its long reach and full-frame coverage. The lens delivered impressive results on full-frame and is a worthy addition to the Pentax lineup.

The build quality of the 150-450mm is stellar. The weather sealed, all-metal body is rugged and durable. Its exterior matches that of other recent Pentax zooms. The textured rings operate smoothly and precisely. It boasts the largest number of external controls on any Pentax lens, with some unique features, like the preset mode and dedicated AF buttons. The tripod foot is the same as on the D FA* 70-200mm— a clever design. The hood is large and, when reversed, covers most of the zoom ring.

Controls are precise and easy to operate, although the large number of closely-packed buttons involves a learning curve. The focus ring is large enough for comfortable use, well-dampened and does not move during AF. The zoom ring is close to the camera body, and has a very long throw at 300°. This means that precise adjustments are easy, although going from one end to the other will involve multiple hand rotations.

Optical results are bordering on the exceptional, especially for such a long zoom. Center sharpness is excellent wide open, making the lens perfectly usable at its widest apertures at all focal lengths. This is eminently desirable for this lens. Edges are generally close to the center, although corners are not as impressive. It is a lens very well suited for isolating subjects— conveniently the most likely use case. Chromatic aberrations and purple fringing are well controlled. Flare is present when the light source is in the center. Ghosting occurs with side illumination when the hood is not used. Vignetting is extremely well controlled, except at the widest focal lengths.

Bokeh is pleasing in most cases, although it can become distracting with busy backgrounds. The rounded aperture blades do their part and bokeh is much better than average, which is commendable especially for a zoom. 

Autofocus, is superb in good light, but not impressive in low light levels. It remains accurate at all times. It is just as reliable in live view and using the viewfinder. Users can switch from one to the other without worries. It is also nearly silent, even though it is possible to hear the large glass elements moving in near-silence. The focus limiter and preset AF position are two very helpful tools which can increase the AF speed. 

The large size of the lens will not come as a surprise for anyone, but must still be taken into account when considering a purchase. This lens belongs on a monopod or sturdy tripod. It is possible to operate it by hand in very good light but there is little point purchasing this expensive lens and risking blurred images. A cheap tripod won't cut it either: vibrations are likely to occur and need to be controlled.

There is little to criticize apart from the size and AF speed in low light. This is a lens designed with a clear purpose in mind. It delivers on that purpose, meeting and often exceeding expectations. It is a worthy addition to the Pentax lineup.

Pros

• Excellent resolution, particularly sharp in the center
• Low distortion
• Chromatic aberration and purple fringing almost absent
• Pleasing bokeh
• Built like a tank
• Numerous, useful external controls
• Fast AF in good light (see con)
• Useful range of focal lengths

Cons

• No internal zooming
• Slow AF in low light
• Some flare and ghosting
• Large and heavy

Pricing

While the HD Pentax-D FA 150-450mm F4.5-5.6 ED DC AW has a full sticker price of $2497 USD, it's average street price in the first half of 2017 was $2270, and the lowest sale price dipped as low as $1995 USD. Prices vary by region.

Rating

Who is it For

The HD Pentax D FA 150-450mm F4.5-F5.6 is a lens meant for varied but well-defined uses. Among those are birding and wildlife, sports, people, street candids and the like. It is not a good choice for low-light photography. Its heavy price tag and weight means that it is not intended for casual shooters but more for users with a specific purpose in mind.

The Bottom Line

The HD Pentax-D FA 150-450mm F4.5-5.6 ED DC AW is a true Pentax lens through and through. It packs a lot of features and superb optical quality, in a rugged and weather-sealed body. Users looking for a lens with these characteristics can consider it with confidence.

The lens can be purchased at authorized dealers worldwide, including B&H Photo— the largest Pentax dealer in the US.  Also, be sure to check the user reviews or post your own if you already own this lens.