Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF)

Most people who own this lens will have bought it as part of a kit with their Pentax SLR. Does the performance warrant upgrading to a higher spec lens? Gary Wolstenholme takes a look.

Much of the time, people will upgrade their kit lens after a while hoping for greater performance and better image quality. Should you break your 18-55mm kit lens, this new version will only cost £130 on it's own as a replacement.

Currently, no third party manufacturers make an equivalent lens in terms of price or specification. If you're looking into alternatives, then I imagine you're looking for an upgrade. The closest third party lens in terms of price and specification is Sigma's 18-50mm f/2.8-4 OS HSM. This lens not only has a brighter aperture through the range, but adds Optical Stabilisation and silent focusing into the mix. It does cost approximately £60 more though.

Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF): Handling and features
As far as kit lenses go, this 18-55mm from Pentax is very well put together. High quality plastics have been used for much of the lens barrel construction, but there are no wobbles or creaks that may be associated with budget lenses. Also the lens mount is made of metal, which should last many a lens change over time. Weighing in at only 220g, this lens should balance well on even the most compact of digital camera bodies.

Focus is powered by the camera body via a lug screw on the lens mount. Even so, Pentax have included their quick manual focus adjustment system, which allows for manual adjustments to be made at any time, just like many will be used to on lenses with silent focusing motors. Personally I feel this is a good compromise. The focus action is very swift on the K-7 used for testing. As the focus ring whizzes back and forth during AF, care needs to be taken not to catch your fingers on the focusing ring. The zoom action feels quite loose, but there is still enough resistance there to prevent any issues with zoom creep.

Close focusing is an impressive 25 centimetres, which should allow for reasonable close ups, even though the lens makes no promises of its macro abilities.

Overall, for a budget lens this optic feels very well put together and the handling is pretty good too.

Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF): Performance
Kit lenses are often panned for their poor performance, but this lens is more than capable of excellent results when used at optimum apertures. At 18mm this optic's performance is nothing short of excellent. At maximum aperture the resolution across the frame is already very good across the frame. Peak quality across the frame is achieved between f/5.6 and f/8 where the resolution across the frame approaches excellent levels.

Zooming to 35mm causes a loss of sharpness at maximum aperture with sharpness in the centre reduced to acceptable levels and the quality towards the edges being fair. At this focal length stopping the lens down improves resolution dramatically. Peak quality across the frame is achieved at f/11 where the sharpness is very good towards the edges and approaching excellent in the centre.

Finally at 55mm, the performance of the lens is much the same as at 35mm. Here it performs slightly better in the centre at f/5.6, but the quality towards the edges can still only be described as fair. Peak quality is now achieved at f/16 where the resolution in the centre approaches excellent and the quality towards the edges approaches good levels.

Resolution at 18mm	Resolution at 35mm
Resolution at 45mm	How to read our graphs The blue column represents readings from the centre of the picture frame at the various apertures and the green is from the edges. Averaging them out gives the red weighted column. The scale on the left side is an indication of actual image resolution. The taller the column, the better the lens performance. Simple. For this review, the lens was tested on a Pentax K-7 using Imatest.

Levels of chromatic aberrations are very low throughout the zoom range and shouldn't be noticeable in normal images. This is excellent performance for a budget lens such as this one.

Chromatic Aberrations at 18mm	Chromatic Aberrations at 35mm
Chromatic Aberrations at 55mm	How to read out charts Chromatic aberration is the lens' inability to focus on the sensor or film all colours of visible light at the same point. Severe chromatic aberration gives a noticeable fringing or a halo effect around sharp edges within the picture. It can be cured in software. Apochromatic lenses have special lens elements (aspheric, extra-low dispersion etc) to minimize the problem, hence they usually cost more. For this review, the lens was tested on a Pentax K-7 using Imatest.

Falloff of illumination towards the corners may be noticeable in certain situations at 18mm. Here Imatest recorded that the corners are 1.31 stops darker than the image centre at f/3.5. Visually uniform illumination is achieved at f/5.6 at this focal length. Vignetting is much less of an issue at 55mm. Here the corners are only 0.652 stops darker than the centre and the transition to the darker areas is so gradual, that it will pose few problems in normal shooting conditions. Images are visually uniform by f/8 at this focal length.

At 18mm, distortion is surprisingly well controlled. Here Imatest only recorded 0.857% barrelling. At 55mm this low level of distortion improves. Here Imatest recorded only 0.306% barrel distortion, which is actually quite difficult to detect by eye. Unfortunately where there is distortion, the pattern isn't uniform across the frame, so care may need to be taken if attempting to correct it for critical applications.

Click on the thumbnails for a high resolution image.
At 18mm the sharpness across the frame is excellent at f/8, plus distortion and CA are kept very low.		At 55mm, there is so little distortion it is very difficult to spot by eye.

Strong point light sources in the frame can cause flare that may be an issue in some cases. The light does have to be very strong in order to do this though, so it shouldn't pose too much of a problem most of the time. As the filter thread does not rotate a petal shaped lens hood comes supplied with the lens, which does an excellent job of shielding the front element from unwanted light that may cause flare or loss of contrast.

DxOMark provides objective, independent, RAW-based image quality performance data for lenses and digital cameras to help you select the best equipment to meet your photographic needs. Visit the DxOMark website for tests performed on the Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF).

Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF): Verdict
As most of you reading this review will probably have received you Pentax 18-55mm lens as part of a kit with your camera, it is well worth taking note of this lens' capabilities before upgrading. If you tend to shoot most of you images with the lens stopped down, or at 18mm, then this optic is capable of delivering very good results. If however you tend to shoot at longer focal lengths and at brighter apertures, then it may be worth looking for an upgrade to make the most of your camera.

Priced at £130 to buy on its own, this lens is firmly seated in the budget end of things, and offers a decent level of performance for the price.

Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF): Pros
Excellent performance at 18mm
Low distortion
Low CA

Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF): Cons
Resolution at 35mm and beyond at maximum aperture
Slightly uneven distortion pattern may be difficult to correct for critical applications

FEATURES
HANDLING
PERFORMANCE
VALUE FOR MONEY
OVERALL

Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF): Lens specification

Price	£130.00
Contact	www.pentax.co.uk
Filter size	52mm
Format	APS-C
Construction	11 elements in 8 groups
Angle-of-view	76 - 29 degrees
35mm equivalent focal length (on APS-C body)	27-82.5mm
Internal focusing	No
Image stabilisation	No (Pentax Stabilisation system is in body)
Minimum focus	25cm
Maximum aperture	f/3.5-5.6
Minimum aperture	f/22-38
Weight	220g
Size	67.5 x 68mm
In the box	Front cap Rear cap Lenshood

The Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF) costs around £130 and is available from Warehouse Express here:

Pentax SMC DA 18-55mm II f/3.5-5.6 ED AL (IF)

Add your message