Pentax DA 16-45mm 1:4 ED/AL review
Introduced way back in December 2003, the SMC DA 16-45mm F4.0 ED AL was Pentax’s first lens specifically designed for digital SLRs, featuring a reduced image circle compared to their existing 35mm lenses, and matched to the dimensions of the APS-C sensor. The design featured an Extra-low Dispersion (ED) glass element and two aspherical elements, promising high quality imaging performance, and Pentax boasted of its compact size and light weight compared to a 35mm format lens with similar specification.
The 16-45mm was clearly aimed at supplementing 35mm users’ existing standard zooms which would lose their wideangle view on the digital sensor, and as such the rather modest 3x zoom ratio corresponds to a 24-70mm equivalent range, essentially covering the wide angle option at the expense of telephoto range. The F4 constant maximum aperture, while by no means remarkable, makes this lens a full stop faster than most comparable zooms at telephoto, whilst helping to keep the size, weight and cost to a reasonable level.
Although digital SLRs have advanced in leaps and bounds in the four years since its introduction, the 16-45mm is still going strong in Pentax's lens range, and indeed has only recently been supplanted by a 16-50mm F2.8 as their premium standard zoom. But in the meantime, it’s arguably been somewhat left behind by newer designs from other manufacturers, which tend to offer much longer zoom ranges as all-in-one ‘walkaround’ solutions. So the question to be answered is whether the 16-45mm is a dinosaur out of step with the modern age, or a golden oldie with much still to offer? Let’s find out.
Headline features
24-68mm equivalent focal length range
F4 constant maximum aperture
'Quick shift' manual focus
KA mount for Pentax APS-C dSLRS onl
The 16-45mm features a decidedly utilitarian design, with far more attention to functionality than aesthetics. It feels reasonably well-made, with construction quality very similar to, and perhaps a notch above, the 18-55mm kit lens (which for once is no bad thing). The lens mount is metal, and the body constructed from metal and high-grade plastics. The extra-wide zoom ring, with its deeply ribbed hard rubber grip, is especially welcome, and a decent manual focus ring with distance scale completes the package. At a lightweight 365g, this is also a lens which you can easily carry on the camera all day long. However it’s not built quite up to the standards of Pentax’s high-end F2.8 SWM zooms, and is not weather sealed to match the K10D or K20D camera bodies.
The most unusual feature of this lens is its ‘reverse zoom’ design, meaning that it is shortest at 45mm telephoto and extends substantially to the 16mm wideangle position. This is rare in a lens of this class, and more usually found in professional-level F2.8 standard zooms. A practical impact is that this gives rise to some shadowing of the built-in flash at wideangle settings.
On the camera
The lens feels well-balanced on the K10D used for testing; the wide zoom ring provides a natural grip for the left hand, and the manual focus ring can be operated readily with just the forefinger. Overall it is a delight to use.
Autofocus
Autofocus is driven by a screw-drive system from the camera body, so AF speed, noise and accuracy is fundamentally dependant on the camera used. On our K10D test body, we found focusing to be generally fast and accurate under most conditions, although with a certain tendency to struggle a bit in low light. Here the faster than usual F4 maximum aperture at the telephoto end confers a noticeable advantage over the 18-55mm kit lens.
Conclusion - Pros
Good 16mm (24mm-equivalent) wide angle and F4 constant aperture
'Quick shift' manual focus override
Decent sharpness and reasonably low chromatic aberration, except at extreme wideangle
Minimal barrel distortion at wide angle
Scarcely any light fall-off at all focal lengths
Excellent macro performance
Conclusion - Cons
Somewhat soft at 16mm
Modest zoom range with short telephoto reach
Flash shadowing at wide angle
Overall conclusion
The Pentax DA 16-45mm F4 ED AL represents an interesting upgrade path from the 18-55mm kit lens, offering a wider angle of view at the expense of shorter telephoto range, coupled with a constant F4 maximum aperture; marginally slower at wideangle, but faster at telephoto. This is in contrast to most other manufacturers’ offerings, which tend towards the general purpose, all-in-one ‘walkaround’ lens with expanded telephoto range. Historically this is because Pentax never designed the 16-45mm as a kit lens upgrade, but as a complement to existing 35mm format lenses in the 28-70mm range; it was therefore intended mainly to cover that otherwise unattainable wideangle view, with no real consideration to the telephoto end.
This means that the decision as to whether this lens is a worthy upgrade to the 18-55mm is slightly complicated, and I must admit to being somewhat sceptical of its usefulness at the start of this test. Sure it has that useful wide angle, but at 45mm it’s a little short for even a head and shoulders portrait; most users would likely still want to pair it with a telephoto zoom for the long end. Also the F4 maximum aperture isn’t exactly going to set the world on fire, although that extra stop at the long end compared to the 18-55mm can be useful. The problems with shadowing of the camera’s built-in flash at wideangle can’t be ignored either. The 16-45mm therefore doesn’t really seem to offer all that much more than the kit lens, and newer lenses with greater zoom ranges or faster maximum apertures also appear to be more compelling options.
But the proof of the pudding is in the eating, and the 16-45mm reveals itself as a fine all-round performer with few faults, both in studio testing and real-life use. It shows pretty consistent image quality across the range, and while the MTF results may not look impressive, its real strengths are elsewhere. In particular it has excellent distortion and falloff characteristics for a wide angle zoom, coupled with reasonable control of chromatic aberration, and impressive macro performance. The only real disappointment is the performance at 16mm, where you'll need to stop down to F11 for best results. And this is all wrapped up in a reasonably small and lightweight package which won’t put much strain on your shoulders. So if your priority is image quality, and the wideangle range floats your boat, this lens is difficult to fault.
Good for: Landscapes, architecture, macro
Not so good for: Portraits, indoor flash
The 16-45mm was clearly aimed at supplementing 35mm users’ existing standard zooms which would lose their wideangle view on the digital sensor, and as such the rather modest 3x zoom ratio corresponds to a 24-70mm equivalent range, essentially covering the wide angle option at the expense of telephoto range. The F4 constant maximum aperture, while by no means remarkable, makes this lens a full stop faster than most comparable zooms at telephoto, whilst helping to keep the size, weight and cost to a reasonable level.
Although digital SLRs have advanced in leaps and bounds in the four years since its introduction, the 16-45mm is still going strong in Pentax's lens range, and indeed has only recently been supplanted by a 16-50mm F2.8 as their premium standard zoom. But in the meantime, it’s arguably been somewhat left behind by newer designs from other manufacturers, which tend to offer much longer zoom ranges as all-in-one ‘walkaround’ solutions. So the question to be answered is whether the 16-45mm is a dinosaur out of step with the modern age, or a golden oldie with much still to offer? Let’s find out.
Headline features
24-68mm equivalent focal length range
F4 constant maximum aperture
'Quick shift' manual focus
KA mount for Pentax APS-C dSLRS onl
The 16-45mm features a decidedly utilitarian design, with far more attention to functionality than aesthetics. It feels reasonably well-made, with construction quality very similar to, and perhaps a notch above, the 18-55mm kit lens (which for once is no bad thing). The lens mount is metal, and the body constructed from metal and high-grade plastics. The extra-wide zoom ring, with its deeply ribbed hard rubber grip, is especially welcome, and a decent manual focus ring with distance scale completes the package. At a lightweight 365g, this is also a lens which you can easily carry on the camera all day long. However it’s not built quite up to the standards of Pentax’s high-end F2.8 SWM zooms, and is not weather sealed to match the K10D or K20D camera bodies.
The most unusual feature of this lens is its ‘reverse zoom’ design, meaning that it is shortest at 45mm telephoto and extends substantially to the 16mm wideangle position. This is rare in a lens of this class, and more usually found in professional-level F2.8 standard zooms. A practical impact is that this gives rise to some shadowing of the built-in flash at wideangle settings.
On the camera
The lens feels well-balanced on the K10D used for testing; the wide zoom ring provides a natural grip for the left hand, and the manual focus ring can be operated readily with just the forefinger. Overall it is a delight to use.
Autofocus
Autofocus is driven by a screw-drive system from the camera body, so AF speed, noise and accuracy is fundamentally dependant on the camera used. On our K10D test body, we found focusing to be generally fast and accurate under most conditions, although with a certain tendency to struggle a bit in low light. Here the faster than usual F4 maximum aperture at the telephoto end confers a noticeable advantage over the 18-55mm kit lens.
Conclusion - Pros
Good 16mm (24mm-equivalent) wide angle and F4 constant aperture
'Quick shift' manual focus override
Decent sharpness and reasonably low chromatic aberration, except at extreme wideangle
Minimal barrel distortion at wide angle
Scarcely any light fall-off at all focal lengths
Excellent macro performance
Conclusion - Cons
Somewhat soft at 16mm
Modest zoom range with short telephoto reach
Flash shadowing at wide angle
Overall conclusion
The Pentax DA 16-45mm F4 ED AL represents an interesting upgrade path from the 18-55mm kit lens, offering a wider angle of view at the expense of shorter telephoto range, coupled with a constant F4 maximum aperture; marginally slower at wideangle, but faster at telephoto. This is in contrast to most other manufacturers’ offerings, which tend towards the general purpose, all-in-one ‘walkaround’ lens with expanded telephoto range. Historically this is because Pentax never designed the 16-45mm as a kit lens upgrade, but as a complement to existing 35mm format lenses in the 28-70mm range; it was therefore intended mainly to cover that otherwise unattainable wideangle view, with no real consideration to the telephoto end.
This means that the decision as to whether this lens is a worthy upgrade to the 18-55mm is slightly complicated, and I must admit to being somewhat sceptical of its usefulness at the start of this test. Sure it has that useful wide angle, but at 45mm it’s a little short for even a head and shoulders portrait; most users would likely still want to pair it with a telephoto zoom for the long end. Also the F4 maximum aperture isn’t exactly going to set the world on fire, although that extra stop at the long end compared to the 18-55mm can be useful. The problems with shadowing of the camera’s built-in flash at wideangle can’t be ignored either. The 16-45mm therefore doesn’t really seem to offer all that much more than the kit lens, and newer lenses with greater zoom ranges or faster maximum apertures also appear to be more compelling options.
But the proof of the pudding is in the eating, and the 16-45mm reveals itself as a fine all-round performer with few faults, both in studio testing and real-life use. It shows pretty consistent image quality across the range, and while the MTF results may not look impressive, its real strengths are elsewhere. In particular it has excellent distortion and falloff characteristics for a wide angle zoom, coupled with reasonable control of chromatic aberration, and impressive macro performance. The only real disappointment is the performance at 16mm, where you'll need to stop down to F11 for best results. And this is all wrapped up in a reasonably small and lightweight package which won’t put much strain on your shoulders. So if your priority is image quality, and the wideangle range floats your boat, this lens is difficult to fault.
Good for: Landscapes, architecture, macro
Not so good for: Portraits, indoor flash
