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Lens review

Pentax smc DA 70 mm f/2.4 Limited

20 November 2009
Szymon Starczewski

4. Image resolution

Even after taking just a few photographs you can tell that the Pentax 2.4/70 is a very well-done instrument, able to produce high quality pictures straight from the maximum relative aperture. Chart tests fully prove this thesis and the results are presented in a picture below.

Pentax smc DA 70 mm f/2.4 Limited - Image resolution

In the frame centre, the lens comes near the 40 lpmm border already by f/2.4 and exceeds it right after f/2.8. At the sharpest apertures – in the range from f/4 to f/8 - we get MTF values close to the record level of 44-46 lpmm. You could hardly have any reservations here.

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The situation is a bit worse for the frame edge but it doesn’t mean there’s something really serious to worry about. Purists might carp about the performance near the maximum relative aperture, where the level of 30 lpmm is just slightly exceeded, but on stopping down to f/4.0 even purists must lose all their arguments.

To sum up: if the Pentax showed a bit better frame edge results, we would have here a near-ideal performance. However, the lens would cost not 550 $ but twice or even thrice that much.

Pentax smc DA 70 mm f/2.4 Limited - Image resolution