TECH ProDuct reviews
If you’re thrown by the somewhat odd focal length of this lens, keep in mind that
since Pentax has no “full-frame” DSLRs (at the time of this writing) the 55mm converts to 84.5mm when attached to the K- 5, which uses an APS-C size image sensor.
That near 85mm length and fast f/1.4 aperture makes it a classic prime lens for
portraits, still-life shots, and low-light photography in general. So while the lenses’
$799 price tag might sound high for a standard 50mm, compare it to the Sigma
85mm f/1.4 ($899) or the Nikkor 85mm f/1.4G ($1,699) and it stacks up quite well.
The black lens’ build feels solid, with a weather-sealed gasket to prevent moisture, dust, and dirt from seeping in. At the same, time the Pentax 55mm lens is fairly
light, weighing just over 13 ounces without the hood. A quick word about the circular cone-shaped hood: it adds nearly two inches to the front of the lens, making it
look either more professional or more conspicuous, depending on your perspective.
Though I liked the hood and always try to use one to protect my best glass while
reducing flare, there’s a stealth appeal to using this lens bare. It’s up to you.
Speaking of stealth, the Pentax 55mm f/1.4’s SDM (supersonic drive motor) keeps
it whisper quiet so you won’t alert or scare shy subjects. I found the autofocus speed
of the lens to be a notch slower than the Sigma and significantly slower than the
Nikon. However, I liked Pentax’s Quick-shift Focus System, which let me override the
autofocus just by twisting the rubberized focus ring to achieve manual lock. This
was great for locking in focus in close-ups of flowers and other plant life. It also
came in handy for beauty shots, letting me zero in on lips, eyelashes and other fine
points to assure sharpness.
The lens did quite well even when shot wide open at f/1.4, producing an extremely
shallow depth of field and beautiful blur behind my model while maintaining sharpness on her eyes. The lens uses rounded diaphragm blades, which helped produce
natural looking circular bokeh in the background.
While you’ll probably want to use the Pentax 55mm mostly at f/1.4 for that distinct, extremely shallow depth of field look, the lens was probably sharpest at f/2.8,
which still produced nice blurring in the background.
Shooting at f/1.4 is really what this lens is made for though and I was happy to
see little to no chromatic aberration in the corners when I shot wide open. Pentax
has placed Aero Bright coating on the internal lens elements to reduce ghosting and
flare and it seemed to do the trick in backlit photos.
Overall, colors were rich and life-like and skin tones were warm and creamy; always a good thing when shooting a model or creating headshots for a client. The
lens also worked well for macro photography, thanks to that vaunted f/1.4 aperture,
which blew out the background and drew attention to the subject of my photos.
I got some terrific shots of flowers but was disappointed that the lens’ minimum
focus distance was only about 18 inches from the subject.
THE BOT TOM LINE
If you’re a Pentax photographer and are serious about portrait photography, the
small and light Pentax DA* 55mm f/1.4 SDM could be the only lens you’ll ever need.
This stealthy little sharpshooter helped us capture great portraits of a model and
fantastic headshots of a singer, with beautiful background blur thanks to the lens’
fast f/1.4 aperture. Though it’s price tag might sound a little high for its focal length,
the quality images you’ll capture with this lens are more than worth it.
Pentax DA* 55mm f/1.4 SDM
Pros: Excellent sharpness even when shot wide open; fast f/1.4 aperture
creates beautiful background blur; superb performance in low light;
Cons: Autofocus speed slower than the competition; big lens hood is