Pentax-DA 14mm f/2.8 ED (IF) Interchangeable Lens Review

This lens from Pentax is an ultra-wide angle offering designed purely for the *istD series of cameras with an APS-C sized sensor with the 1.5x crop factor. As a means of overcoming the wide angle limitations of cropped sensors, does it go far enough? We take a look.

Specifications

• Focal Length 14mm
• Max Aperture f/2.8
• Min Aperture f/22
• No of Blades 9
• Angle of view 90º
• Filter size 77mm
• Construction 12/11 elements/groups
• Focus type AF/MF
• Closest focus 0.17m (0.19x)
• Weight 420g (ex hood)
• Dimensions 83.5x69mm
• Mounts available Pentax KAF
• Tripod bush No
• Price (SRP) £699.99p

Build and handling
Outwardly the lens is of a simple construction and is supplied in a soft, Velcro closing pouch. It is designed for the auto-only cameras of the *istD range, so forward of the mount the first item is a distance window marked in metres and feet as well as a useful depth-of-field scale. The only control on the lens is the manual focus ring, a rubber ribbed affair some 15mm wide that comes immediately in front of the window. It is well torqued to the extent that it was slightly stiff when new. A bayonet-fit perfect hood is supplied with the lens. With a 77mm filter thread, a popular size with ultra wide angles, there were no vignetting problems using the Cokin Z-Pro system and being an internal operating lens, the front element did not rotate during auto or manual focussing. Overall the build felt solid without being over-weight.

Optical Performance
For the price, this lens was disappointing in the optical performance stakes under test conditions. However the actual performance of the lens was not as bad as the figures make out! Chromatic Aberration was evident at the edges of the frame, although reasonably well controlled at the centres and a little barrel distortion was detected (3.89%) although not enough to be a nuisance. What was surprising and a little disconcerting was the inability to produce consistent results from the tests that were run three times on two occasions. The results given here are the best of those runs but it goes a long way to showing how much influence the camera has on the results in this digital age, given that the lens is a fixed focal length and not much can vary! This is despite the fact that the tests are all carried out in RAW format.

Looking down on the interior courtyard of Bodiam Castle in East Sussex the lens was wide enough to capture the scale of the scene. Pentax *istDS. 1/200sec at f/11 Set up on a tripod, this framed scene of the castle was well within the lens capability. *ist DS, 1/180sec at f/16

Without being able to step a little further back it was not quite possible to get the whole picture in the frame and the top of the tower had to be cut off. *istDS, 1/90sec at f/16

Click on each comparision photo below to view full size versions

14mm set at f/8

14mm set at f/2.8

Below is our lens test data. To find out how to use these graphs look at this article: How we test lenses

Verdict
With a crop factor of 1.5x on the *istD cameras, this equates to a field of view similar to 21mm on a 135 format camera and is a little less wide than most of the opposition are achieving at the present time. On top of this, the performance of this lens wide open is not as good as it could be, especially given the price. Along with the other little niggles on picture quality that should not occur in a modern design of lens I was rather disappointed.

In summary, the positive points of the Pentax DA 14mm f/2.8 ED (IF) are:
Good build quality
Nice protective pouch

The negative points are:
Optically disappointing, especially wide open
High price for performance

Check the latest price for the Pentax 14mm f/2.8 DA here

Test by Ian Andrews www.wildaboutkent.co.uk