Pentax DA 40 and 70mm Limited lens coverage with Pentax K10D
The Pentax DA 40mm f2.8 and 70mm f2.4 Limited lenses have effective focal lengths of 60 and 105mm respectively when mounted on a Pentax DSLR. This gives them almost standard and short telephoto coverage respectively.
To illustrate their coverage in practice, we shot the same scene with each lens within a few moments of each other from a tripod to ensure a consistent position. To show how their coverage compares to the standard kit lens, we’ve also included samples from the DA 18-55mm f3.5-5.6. So below from left to right are the Pentax DA 18-55mm at 18mm, followed by the DA 40mm f2.8 Limited, the DA 18-55mm zoomed-into 55mm and finally the DA 70mm f2.4.
Pentax DA 18-55mm at 18mm
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Pentax DA 40mm f2.8 |
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Pentax DA 18-55mm at 55mm |
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Pentax DA 70mm f2.4 |
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18-55mm at 18mm
(27mm equiv) |
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40mm
(60mm equiv) |
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18-55mm at 55mm
(83mm equiv) |
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70mm (105mm equiv) |
The samples above have no surprises: the DA 40mm f2.8 Limited delivers roughly the same coverage as mid-way through the kit lens range, while the DA 70mm f2.4 Limited is slightly more powerful. The DA 40mm is just a little longer than a standard lens in practice, while the DA 70mm offers short telephoto capabilities. See our Gallery page for portrait and landscape samples.
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Pentax DA 40 and 70mm Limited lens aperture
The DA 40 and 70mm Limited lenses have maximum focal ratios of f2.8 and f2.4 respectively. Both provide a bright view when composing, decent flexibility in low light and the potential to create very small depth-of-fields. The DA 70mm is particularly good in this regard and makes an ideal portraiture lens – see our Gallery for examples.
Pentax Shake Reduction with the K10D and DA 70mm Limited
The DA 40 and 70mm Limited lenses don’t feature optical stabilisation, but mount them on either the K10D or K100D bodies and their built-in Shake Reduction systems will extend the range of shutter speeds you’ll safely be able to handhold. For a full report on how the Pentax Shake Reduction system works, see our Pentax K10D review, but in the meantime, here’s an excerpt with examples taken using the DA 70mm lens.
In use we found the K10D’s Shake Reduction system certainly allowed us to handhold longer exposures than normal, but we rarely achieved more than two stops of compensation. During numerous tests, the biggest difference between an image taken with and without Shake Reduction can be seen below. Both images were taken moments apart using the K10D fitted with the DA 70mm Limited Edition lens, thereby working at an effective focal length of 105mm.
With the aperture closed to f22 at 100 ISO, the shutter speed was 1/8 of a second. We cropped an area from each image measuring 564x272 pixels, then reduced it to 282x136 pixels for reproduction here; you’re therefore viewing the images at 50%.
Pentax DA 70mm with K10D
Shake Reduction OFF
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Pentax DA 70mm wit K10D
Shake Reduction ON |
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70mm (105mm equiv), 1/8, f22, 100 ISO |
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70mm (105mm equiv), 1/8, f22, 100 ISO |
The image above right with Shake Reduction enabled may not be 100% sharp (even when viewed at 50%), but it does show a great improvement over the image above left. When we increased the shutter speed to the point where both images were 100% sharp though, there were only two stops difference. Like all anti-shake systems though, the effectiveness varies between people and situations. The bottom line is the K10D’s Shake Reduction system certainly made a difference, but not as much as experienced with other image stabilisation systems.
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