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Pentax 16-45mm/4 Lens Review

by Josh Root, August 2007


The Pentax SMC DA 16-45mm f/4.0 ED/AL is a fairly-compact wide zoomlens with a high image quality and a lower price than that of similarofferings from other manufacturers. This lens covers the wide toshort-telephoto range and can do everything from capturing candidphotos in a crowded room to creating nice portraits of a couple orsmall group. One of the most useful lenses that a photographer canhave is a mid-range zoom.

The DA designation signifies that the lens is specifically designedfor Pentax mount digital SLR bodies, which helps to keep the weightand size down. The ED designation signifies that the optical elementsare made with "extra-low dispersion" glass, a more expensive andhigher-quality material. The focal length of this lens makes it anexcellent choice as an upgrade to the cheaper "kit" lens that istypically packaged with digital SLRs. The fact that this lens is not a2.8 lens can be a limiting factor for the advancedphotographer. However, due to the fact that this is a wide-angle lens,and its only one stop slower than 2.8, most photographers will beable to compensate with a lower shutter speed or higher ISOlevel. Photographing indoors using available light is more of achallenge than with a 2.8 zoom or a 1.8 prime lens, though the 16-45still performs well in these conditions.

If you have a Pentax K10D, (buy from Amazon) (review),Pentax K100D, (buy from Amazon), or other Pentax mount DSLR, and needa wide to short-telephoto zoom, buyone right now from amazon.com and help to support photo.net.

Performance

As with all of the DA series lenses, the Pentax 16-45s image circleis sized to cover the APS-C sized CCD in Pentax DSLR cameras, cuttingdown on weight and size. The focal length range is 16-45mm, which isequivalent to 24.5-69mm in 35mm format. 24mm is about as wide of anangle of view as you can get without starting to get the distortionand optical effects that wide-angle lenses have. 70mm is a nicemid-telephoto portrait length, allowing you to avoid the unflatteringeffects of wide angle lenses when doing portrait photography.

However, the f/4 aperture wont be helpful in creating a shallow depthof field for your portrait image. As this is a wide-angle lens, youwould have a hard time doing that anyway. If you are looking for aportrait lens with the ability to create a very shallow depth offield, you might be better off with a fast prime like thePentax DA 70mm f/2.4 Limited, (buy from Amazon) (review). The focal length of the Pentax 16-45makes it a good choice for scenic or environmental portraiture. Due tothe slower AF speed, capturing fast-moving action is somewhatchallenging. Autofocus is slow when compared to the internal motorstyle of Canons USM or Nikons AFS. The Pentax is driven by the oldNikon-style "screwdriver blade" body motor. If you demand lens-motordriven AF for your Pentax DSLR in this focal length, you mightconsider the soon-to-be-released (as of Aug 07)Pentax DA* 16-50mm f/2.8 ED AL IF SDM, (buy from Amazon). If hyper-fast autofocus is not yourmain concern, the 16-45s AF will be satisfactory.

Optics

The Pentax 16-45 is a complex lens design, with 13 elements in 10groups including two aspherical lenses and ED elements (Extra-lowDispersion glass). There is noticeable barrel distortion at the wideend of the lens. This barrel distortion is not out of line for a lensof this focal length. Sharpness is quite good for a lens of this priceand zoom range. Unsurprisingly, center sharpness is frequently betterthan corner sharpness on the wide end, but corner sharpness issurprisingly good as well. Most interesting is that, unlike manylenses in this focal range, the Pentax 16-45 does not lose muchsharpness when used wide open.

Construction

When using the included petal-shaped lens hood, the smart designallows the 67mm filter and lens cap to be threads-free. Thereverse-mounted hood allows access to the easy-to-grip zoom ring, butblocks the manual focus ring. As with all DA-series lenses, Pentaxincludes the Quick-Shift Focus System on the 16-45, which is similarto the Full-Time Manual Focus on some Canon lenses. Unfortunately, thePentax 16-45s manual focus ring is not as nice as it could be. As itis, the ring is small, hard to find quickly without looking, rotatesduring AF, and seems to be added on as an afterthought. It also hasthe awful chintzy feel in use, typical of modern AF lensesirrespective of manufacturer. Of note, Pentax has remained dedicatedto manual focus and actually includes the MF ring and distancemarkings on the 16-45. One unusual feature of this lens is that thelens extends when zoomed to the wide end of the focal range. That isto say, the lens is at its most compact size when set at 45mm. Whilenot common, a few other popular lenses operate this way, most notablythe Canon 24-70/2.8.

Weight is 12.9 oz (365g), which balances quite well with thePentax K10D, (buy from Amazon) (review). The lenss dimensions are a fairlycompact 2.8in x 3.6in (92 x 72 mm).

Alternatives

Here are some other lens options to consider:

Conclusion

Overall, the Pentax SMC DA 16-45mm f/4.0 ED/AL is a very nice lensthat could find its way into any photographers Pentax DSLR camerabag. It is priced so that a beginner would consider it as an upgradeto their "kit" lens. Yet it also has the image quality and well builtconstruction that would give the more experienced photographer reasonsto 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 2.8constant aperture, the constant f/4 aperture is only a single stopslower and many will consider the smaller size and significantly lowerprice more than worth the trade off.

Where to Buy

You can get this lens overnight from amazon.com.

Specifications

Focal Length 16-45 mm
Maximum/Minimum Aperture f/4 f/22
35mm equivalent focal length (PentaxDSLR) 24.5-69 mm
Lens Construction 13 elements in 10 groups, 1ED and 2 aspherical elements
Minimum Shooting Distance 0.92 ft(0.28 m)
Aperture Blades 6 blades
Filter Size 67 mm
Dimensions (Diameter x Length) 2.8" x 3.6" (7.2x 9.2 cm)
Weight 12.9 oz (366 g)

More

Examples

29mm, f/6.7, 1/500th, ISO 200. The wide end of the 16-45 gave me alarge enough field of view to capture this jugglers performance whilestill staying at the front of the crowd.

16mm, f/6.7, 1/250th, ISO 200. Another street performer photographedin motion. Again, the wide end of the Pentax 16-45 allowed me tocapture the excitement of the moment and add some drama into thephoto.

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 longend to isolate these two and bring the focal point to the mirrorsreflection.

50mm, f10, 1/250, ISO 200. While the AF is not blazingly fast, thelens did respond quickly enough to allow me to take some weddingimages.

34mm, f/6.7, 1/180, ISO 100. The 16-45 on a Pentax K10D is a nicerange for images of groups of people.

36mm, f/5.6, 1/180, ISO 400. Yes, that is exactly what you think itis, 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 streetphotography, and I usually prefer something with a faster maximumaperture. In this case I didnt need it. Since there wasnt room toback up further, I could have used 1 or 2 mms more on the wide end inorder to get the womans head in completely on the right.


Text and pictures ©2007 Josh Root. All images were captured usingthe Pentax K10D, (buy from Amazon) (review), camera body.

Article created August 2007

Readers Comments




Phil Liao , August 27, 2007; 02:25 P.M.

I have this 16-45 lens and the 18-55 kit lens. The picture quality differences from these two lenses are barely noticeable. However, 16mm wide angle (24mm equivalent) is quite important to me.

The recent unofficial lens tests of the 16-50 f/2.8 by other people on various forums have been disappointing. The SDM is not very fast and the picture quality is on par with the 16-45. It is heavy and expensive as well, though f/2.8 is very important to many shooters.

On the long end, the 50 f/1.4 is incredible and not too expensive. The 70 f/2.4 and 77 f/1.8 might be more suitbale focal lengths for traditional portraits though. The mystical 85 f/1.8 and f/1.4 are nearly impossible to find these days.

Stephen Graham , September 07, 2007; 05:29 A.M.

Ive also got both the 16-45 and the 18-55 and my experience differs from the previous poster in that I find the 16-45 significantly better, especially with regards to corner sharpness where Ive found the 18-45 a fairly poor performer - even stopped down.

So far Ive been quite happy with the 16-45, ok F4 is still quite slow however its a decent size/weight compromise and a good general purpose lens. The relatively short 45mm long end isnt a concern for me because Im lucky enough to own one of the "mystical" FA* 85mm F1.4s mentioned by the previous poster!

Michael Kuhne , September 17, 2007; 10:49 P.M.

While not a super expensive f/2.8 pro lens, f/4 is not slow for this focal range- but still faster than average. f/2.8 is as fast as it gets. 16mm also provides a wider angle view than average for a wide-to-short-tele zoom. On top of this, being very sharp center to corner throuout its range makes this lens an excellent value.

Bella Lee , December 31, 2007; 02:14 P.M.

I highly recommend this lens if F/4 is all you need. It delivers clarity, sharpness and contrast comparable to fix focal length lenses in this range. Beside ,the fact that it is sharp wide open and has strong close-foucsing performance makes the DA 16-45 vastly superior to the kit lens (DA 18-55). With its price dropping after the introduction of the DA* 16-50, this little brother is truly a cost-performance champion against which all standard zooms should be measured.

Robin Parmar , April 09, 2008; 06:38 A.M.

This lens is commonly available at a bargain price. I literally have not mounted my kit lens since purchasing it. I find it is wonderful for cityscapes and urban shots, but also used it on a recent landscaping outing with nice results. I cannot compare with the DA* 16-50 but this is much less expensive. The lens extends enough at wide-angle to make this too prominent for indoor candid shots in some situations. I will wait on the upcoming 15mm limited for that. Competing f/2.8 lenses are heavier and have poorer IQ so I am not tempted. The 16-45 hits a sweet spot for me.