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The Pentax SMC DA 16-45mm f/4.0 ED/AL is a fairly-compact wide zoom
lens with a high image quality and a lower price than that of similar
offerings from other manufacturers. This lens covers the wide to
short-telephoto range and can do everything from capturing candid
photos in a crowded room to creating nice portraits of a couple or
small group. One of the most useful lenses that a photographer can
have is a mid-range zoom.
The DA designation signifies that the lens is specifically designed
for Pentax mount digital SLR bodies, which helps to keep the weight
and size down. The ED designation signifies that the optical elements
are made with "extra-low dispersion" glass, a more expensive and
higher-quality material. The focal length of this lens makes it an
excellent choice as an upgrade to the cheaper "kit" lens that is
typically packaged with digital SLRs. The fact that this lens is not a
2.8 lens can be a limiting factor for the advanced
photographer. However, due to the fact that this is a wide-angle lens,
and it's only one stop slower than 2.8, most photographers will be
able to compensate with a lower shutter speed or higher ISO
level. Photographing indoors using available light is more of a
challenge than with a 2.8 zoom or a 1.8 prime lens, though the 16-45
still performs well in these conditions.
As with all of the DA series lenses, the Pentax 16-45's image circle
is sized to cover the APS-C sized CCD in Pentax DSLR cameras, cutting
down on weight and size. The focal length range is 16-45mm, which is
equivalent to 24.5-69mm in 35mm format. 24mm is about as wide of an
angle of view as you can get without starting to get the distortion
and optical effects that wide-angle lenses have. 70mm is a nice
mid-telephoto portrait length, allowing you to avoid the unflattering
effects of wide angle lenses when doing portrait photography.
However, the f/4 aperture won't be helpful in creating a shallow depth
of field for your portrait image. As this is a wide-angle lens, you
would have a hard time doing that anyway. If you are looking for a
portrait lens with the ability to create a very shallow depth of
field, you might be better off with a fast prime like the
Pentax DA 70mm f/2.4 Limited, (compare prices) (review). The focal length of the Pentax 16-45
makes it a good choice for scenic or environmental portraiture. Due to
the slower AF speed, capturing fast-moving action is somewhat
challenging. Autofocus is slow when compared to the internal motor
style of Canon's USM or Nikon's AFS. The Pentax is driven by the old
Nikon-style "screwdriver blade" body motor. If you demand lens-motor
driven AF for your Pentax DSLR in this focal length, you might
consider the soon-to-be-released (as of Aug '07)
Pentax DA* 16-50mm f/2.8 ED AL IF SDM, (compare prices). If hyper-fast autofocus is not your
main concern, the 16-45's AF will be satisfactory.
The Pentax 16-45 is a complex lens design, with 13 elements in 10
groups including two aspherical lenses and ED elements (Extra-low
Dispersion glass). There is noticeable barrel distortion at the wide
end of the lens. This barrel distortion is not out of line for a lens
of this focal length. Sharpness is quite good for a lens of this price
and zoom range. Unsurprisingly, center sharpness is frequently better
than corner sharpness on the wide end, but corner sharpness is
surprisingly good as well. Most interesting is that, unlike many
lenses in this focal range, the Pentax 16-45 does not lose much
sharpness when used wide open.
When using the included petal-shaped lens hood, the smart design
allows the 67mm filter and lens cap to be threads-free. The
reverse-mounted hood allows access to the easy-to-grip zoom ring, but
blocks the manual focus ring. As with all DA-series lenses, Pentax
includes the Quick-Shift Focus System on the 16-45, which is similar
to the Full-Time Manual Focus on some Canon lenses. Unfortunately, the
Pentax 16-45's manual focus ring is not as nice as it could be. As it
is, the ring is small, hard to find quickly without looking, rotates
during AF, and seems to be added on as an afterthought. It also has
the awful chintzy feel in use, typical of modern AF lenses
irrespective of manufacturer. Of note, Pentax has remained dedicated
to manual focus and actually includes the MF ring and distance
markings on the 16-45. One unusual feature of this lens is that the
lens extends when zoomed to the wide end of the focal range. That is
to say, the lens is at its most compact size when set at 45mm. While
not common, a few other popular lenses operate this way, most notably
the Canon 24-70/2.8.
Weight is 12.9 oz (365g), which balances quite well with the
Pentax K10D, (compare prices) (review). The lens's dimensions are a fairly
compact 2.8in x 3.6in (92 x 72 mm).
Overall, the Pentax SMC DA 16-45mm f/4.0 ED/AL is a very nice lens
that could find it's way into any photographer's Pentax DSLR camera
bag. It is priced so that a beginner would consider it as an upgrade
to their "kit" lens. Yet it also has the image quality and well built
construction that would give the more experienced photographer reasons
to purchase it as well. When comparing its price to its image quality,
the 16-45 is a very good value. Although the 16-45 does not have a 2.8
constant aperture, the constant f/4 aperture is only a single stop
slower and many will consider the smaller size and significantly lower
price more than worth the trade off.
29mm, f/6.7, 1/500th, ISO 200. The wide end of the 16-45 gave me a
large enough field of view to capture this juggler's performance while
still staying at the front of the crowd.
16mm, f/6.7, 1/250th, ISO 200. Another street performer photographed
in motion. Again, the wide end of the Pentax 16-45 allowed me to
capture the excitement of the moment and add some drama into the
45mm, f4, 1/90, ISO 400. While the wide end of the zoom has its uses,
in this case I was pleased to have just enough zoom on the long
end to isolate these two and bring the focal point to the mirror's
50mm, f10, 1/250, ISO 200. While the AF is not blazingly fast, the
lens did respond quickly enough to allow me to take some wedding
34mm, f/6.7, 1/180, ISO 100. The 16-45 on a Pentax K10D is a nice
range for images of groups of people.
36mm, f/5.6, 1/180, ISO 400. Yes, that is exactly what you think it
is, a stump with a bunch of old chainsaws stuck in it. What can I say,
I love logging shows.
16mm, f/5.6, 1/60, ISO 400. F/4 is a little slow for street
photography, and I usually prefer something with a faster maximum
aperture. In this case I didn't need it. Since there wasn't room to
back up further, I could have used 1 or 2 mm's more on the wide end in
order to get the woman's head in completely on the right.