Pentax DA 12-24mm f/4 AL ED [IF] - Review / Test Report
Lens Reviews -
Wednesday, 26 December 2007 05:46
Page 1 of 3
Special thanks to Jens Rösner for providing this lens for testing!
The Pentax DA 12-24mm f/4 AL ED [IF] is the result of a cooperation between Pentax and Tokina.
However, the two lens variants are not identical - that's most obvious regarding the outer construction
and cosmetics but the Pentax lens does naturally also feature Pentax' own SMC lens coating.
Just like its Pentax DA-type brothers and sisters it is a lens with a reduced image circle with
a field-of-view is equivalent to 18-36mm on full format cameras - a typical ultra-wide zoom lens.
The build quality of the Pentax lens is very fine thanks to a combination of metal and plastic parts
assembled with tight tolerances. The zoom ring as well as the rather small focus ring operate
smooth and slightly damped. The lens has its shortest physical length in the middle of the zoom
range and it extends marginally towards the 12mm and 24mm setting.
The front element does not rotate so using a polarizer remains easily possible.
Typical for most Pentax lenses the DA 12-24mm f/4 AL ED [IF] has no internal AF motor and
relies on a slotted drive screw operated by the camera. Consequently AF operations
generate a moderate degree of noise. The AF speed is very fast on the K10D. The tested
sample showed a quite pronounced back-focus problem.
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||18-36 mm (full format equivalent)|
|Equiv. aperture||f/6 (full format equivalent, in terms of depth-of-field)|
|Optical construction||15 elements in 12 groups inc. 1 ED and 2 aspherical elements|
|Number of aperture blades||8|
|min. focus distance||0.30 m (max. magnification ratio 1:8.3)|
|Dimensions||84 x 88 mm|
|Filter size||77 mm (non-rotating)|
|Hood||petal shaped (supplied)|