Pentax SMC-DA 50-200mm f/4-5.6 ED - Review / Test Report
Lens Reviews -
Wednesday, 26 December 2007 01:57
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The Pentax SMC-DA 50-200mm f/4-5.6 ED is currently the longest tele lens in the
Pentax lens lineup. It is usually sold as part of camera kits but it is
also sold separately for as little as 160€/US$ and as such obviously an
offer for budget shoppers. Typical for DA series lenses it is dedicated to the APS-C
sensor format where its field-of-view is equivalent to 75-300mm in classic terms.
The first striking feature of the DA 50-200mm is its size. Normally you would expect
a tele lens to be fairly big and massive but the Pentax lens is a tiny being and not much
bigger than the standard kit zoom. Despite the very low price tag the build quality
of the lens is surprisingly decent. Naturally the outer construction is still based
on lots of plastics but its quality is quite fine with relatively tight gap tolerances
and there's even a metal mount. Unlike most kit lenses from other manufacturers the
DA 50-200m ED does also features a usable, dedicated focus ring. Both the zoom and focus
ring operate smooth. As you can see below the lens extends significantly when zooming
towards the long end of the zoom range. There're two inner tubes ("duo cam") although
the innermost one is only used by the focusing system. The front element does not rotate
so using a polarizer is no problem.
The lens has no internal AF motor and relies on a slotted drive screw operated by
the camera. As a result AF operation will generate a moderate degree of noise.
The AF speed is reasonably fast although a little unsure at times and it's fairly
accurate on the K10D. Thanks to a "Quick-Shift Focus System" manual focusing is
instantly possible once the AF has achieved focus - this works very well and noiseless.
|Equiv. focal length||75-300 mm (full format equivalent)|
|Equiv. aperture||f/6-f/8.4 (full format equivalent, in terms of depth-of-field)|
|Optical construction||11 elements in 10 groups inc. 1 ED element|
|Number of aperture blades||6|
|min. focus distance||1.1 m (max. magnification ratio 1:4)|
|Filter size||52 mm (non-rotating)|
|Hood||barrel shaped, snap-on type (supplied)|
|Other features||Quick-Shift Focus System|