Pentax 16-45mm f/4 SMC DA ED AL Lens Review

A standard 16-45mm zoom for Pentax digital SLR cameras providing a wide angle view equivalent to 24mm on a 35mm camera and a constant f/4 maximum aperture.

Posted: 28/10/2010 - 14:22

Handling and features
Performance
Verdict
Specification

Sitting in the middle of Pentax's lens range, the 16-45mm offers a moderately bright aperture of f/4 throughout the zoom range and a useful wide angle field of view equivalent to 24mm on a 35mm camera. The lens costs around £230, which isn't too pricey for a marque lens of this specification. Above this in Pentax's lens range is the 16-50mm f/2.8, which can be bought for around £695. Apart from having a brighter maximum, this lens also sports Pentax's SDM silent focusing motor.

Suitable alternatives from third party manufacturers include Tamrons 17-50mm f/2.8, which has a brighter f/2.8 aperture throughout the zoom range, but costs around £330. Sigma's 17-70mm OS HSM has Optical Stabilisation you can see working through the viewfinder and a silent focusing moor, but cost about the same as the Tamron.

Pentax 16-45mm f/4 SMC DA ED AL Handling and features

Much of the lens barrel on the 16-45mm is made of lightweight, yet high quality plastics that feel quite robust and rigid. The zoom mechanism works the opposite way to what you might think, with the lens being at its longest at 16mm, and its shortest just before 45mm. The supplied petal shaped lens hood clips onto the front of the lens and moves with the zooming action, which is unlike other lenses of this design where the lens zooms inside the hood, This means the hood won't be as effective as it could be at shielding the front element from extraneous light as it could be at 70mm.

The zoom mechanism is smooth and quite loose between 16mm and 35mm. For the last 10mm it tightens up a bit, but is still quite easy to adjust even here. I had no issues with zoom creep during use despite the zoom ring feeling quite loose.

Focus is powered by the screw-driven motor in the camera and is quite responsive and quick to obtain a lock in a wide range of condition on the K-7 used for testing. A full time manual focus feature allows the focus to be adjusted at any time, just like on lenses with silent focus motors, which is a nice addition.

Weighing only 365g, this lens is quite lightweight and at 92mm long it isn't too large either, which should make it an ideal companion for travelling photographers, or those who just wish to travel light.

Overall the lens feels well put together and responsive to focus. I really enjoyed using it due to this and the lightweight and compact design.

Pentax 16-45mm f/4 SMC DA ED AL Performance

This lens performs well throughout the range, starting off strong at 16mm and getting good again at 45mm. At 16mm and maximum aperture the sharpness is already very good in the centre and the quality towards the edges is acceptable. Stopping the lens down improves the sharpness across the frame as far as f/8, where the resolution is excellent across the frame.

Zooming to 28mm causes a slight loss of sharpness at each aperture, but the quality at maximum aperture is generally more than acceptable. At f/4 the centre sharpness approaches good levels and the quality towards the edges is fair. Peak quality is achieved at f/11 where the sharpnes in the centre is very good and the quality towards the edges is good.

Finally at 45mm the sharpness in the centre at maximum aperture is already very good with good sharpness produced towards the edges. Here peak quality across the frame is achieved at f/8, where the resolution is very good across the frame.

Pentax SMC DA 16-45mm f/4 ED AL MTF Charts

Chromatic aberrations are well controlled with levels staying well below noticeable levels until 45mm. Here fringing increases at maximum aperture to around 0.9 pixel widths towards the edges, which may become noticeable in large prints with high contrast edges towards the edge of the frame.

Pentax SMC DA 16-45mm f/4 ED AL Chromatic Aberration Charts

At 16mm falloff of illumination towards the corners is very well controlled. Here Imatest recorded a barely noticeable level of vignetting of 0.7stops. Stopping down to f/5.6 results in visually uniform illumination. This low level of falloff remains constant throughout the zoom, which is excellent performance for a lens of this type.

Distortion is also very well controlled. At 16mm Imatest recorded only 1.36% barrel distortion, which should only pose an issue in the most critical of applications. At 45mm Imatest could only detect 0.306% barrelling, which is amongst the lowest levels I have seen on a zoom lens. Unfortunately the distortion pattern isn't constant across the frame, so care will need to be taken correcting the curvature of lines if it does become an issue. Still with such a low level present I believe most people will be able to live with this.

This lens is reasonably resistant to flare and ghosting. Strong point light sources in the frame will cause a slight loss of contrast and some flare, but not so much that the lens is unusable under these conditions. Light sources just outside of the frame may also cause flare if the supplied lens hood isn't fitted. This hood is a petal shaped type and it does an excellent job of keeping unwanted light off the front element.

Pentax SMC DA 16-45mm f/4 ED AL Sample Photos

Pentax 16-45mm f/4 SMC DA ED AL Verdict

This lens is generally a very good performer and it doesn't cost much either. In my mind this is the ideal standard zoom lens for use with Pentax digital SLRs if you don't require a faster aperture than f/4 or an obnoxious zoom range.

For the price the levels of sharpness are excellent. Coupled with the low distortion and low levels of colour fringing it makes the lens a very attractive prospect indeed.

Pentax SMC DA 16-45mm f/4 ED AL Specifications

Members gallery photos using: smc PENTAX-DA J 16-45mm F4 ED/AL

Shawnbo Shawnbo

Posted 24/12/2023 - 23:39 Link

Don't let the age of this lens design fool you - this is a sleeper, one of Pentax's best DA zooms. I found one three years ago, new in open box, that the retailer was dumping at a 75% discount. I didn't need it, but bought it anyway, as used examples were selling for three times the money at the time. It's a brilliant lens, almost without fault. I've even used it for some very decent astrophotography, despite its f4 max aperture. A semi-pro optic for a pittance.

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