Sony 30mm f/2.8 DT macro ( SAL-30F28 ) - Lab Test / Review
Lens Reviews -
Sony Alpha/NEX (APS-C)
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Review by Klaus Schroiff, published November 2010
Lens kindly provided by Renwei Chen!
The Sony 30mm f/2.8 DT is a budget macro prime lens for the Sony Alpha system. As a designated DT ("Digital Technology") lens it is compatible to APS-C DSLRs only. Just like most recent DT lenses it features the new SAM ("Smooth Autofocus Motor") so it no longer depends on the dated AF drive screw system which is still used by many Sony/Zeiss lenses.
The build quality of the lens is average at best. The lens barrel is completely made of plastic and that's including the lens mount. It uses a linear extension system for focusing - the, slightly wobbly, inner lens tubes extend somewhat during the process. The tiny focus ring at the lens front operates smoothly. It remains coupled to the AF motor in AF mode so it rotates during AF operations. However, the filter ring does not rotate.
The SAM AF drive is reasonably fast but it's not a speed demon either. DMF ("Direct Manual Focusing") is not supported. The working distance (lens front to object) is just 2cm at 1:1 magnification - this can be a limiting factor if you're into creepy critter photography.
|Equiv. focal length||45 mm (full format equivalent)|
|Equiv. aperture||f/4.2 (full format equivalent, in terms of depth-of-field)|
|Optical construction||6 elements in 5 group|
|Number of aperture blades||7 (rounded)|
|min. focus distance||0.13 m (max. magnification ratio 1:1)|
|Dimensions||70 x 45 mm|
|Filter size||49 mm (non-rotating)|