Sony DT 30mm f/2.8 Macro SAM: Dual Attraction

Sony DT 30mm f/2.8 Macro SAM

Shridhar Kunte tests the Sony DT 30mm f/2.8 Macro SAM to see if this lens offers anything apart from its attractive low price.

Sony’s fortunes in the interchangeable-lens camera market have seen a revival with the new NEX and SLT cameras. However, the availability of lenses has always been a problem, especially in India. The DT 30mm f/2.8 Macro SAM is an interesting product though. Not only is it really economical, but also seems to be a versatile product on paper. Let us see if the performance matches up.

Features
This 1:1 macro lens is targeted at entry-level DSLR users. When mounted on Alpha bodies it gives an effective focal length of 45mm with a fast aperture of f/2.8, thus making it a fast normal lens as well. The minimum focusing distance is 0.13m, at which the magnification ratio is life size. This is not ideal for a macro lens, as you do not have a good working distance. It also becomes very difficult to light the subject at such close proximity. In fact, one can easily say that while this is a 1:1 macro lens, if you want to work comfortably, the magnification ratio you can achieve is only half of life size.
The lens construction is extremely simple—there are six elements arranged in five groups. To my surprise, there is no special (aspherical or ED) glass element, which made me doubt the potential optical performance before actually using the lens.
Considering the fact that all Sony DSLR and SLT cameras have sensorshift stabilisation, the camera-lens combination automatically gets stabilised. The lens accepts 49mm filters. For a lens with a maximum aperture of f/2.8, it is great that the diameter has been kept this low, because the filters for this lens will be less expensive.

Handling
The lens balances perfectly on the Sony SLT Alpha 55 body. With the overall weight of 150g, the lens feels really light. The internal components are mostly engineering grade plastic, including the lens mount, which is also made of plastic. All this gives a cheap feel to the lens.
During focusing, the front lens group moves, but the front element itself does not rotate. This makes it easier for someone to work with polarising filters or even ring flashes. The AF/MF switch is easy to reach with the left thumb, while keeping a firm grip over the lens barrel.
The focusing ring is narrow, but can be easily rotated for manual focusing. The lens has a rotation of 90° in which it focus from infinity to 13cm. The focusing distance scale is clearly marked in feet as well as metres, but I felt the need of depth-of-field scale which was missing on the 30mm f/2.8.

Performance
With the look and feel of this lens, I was not expecting too much in terms of quality, but I was proved wrong. The 30mm is quite a good performer. In terms of AF accuracy, the lens is quite good, when capturing subjects at the minimum focusing distance, but it gives mixed results when focused at infinity.
The Smooth Autofocus Motor enables quick AF, but the operation is not silent at all, unlike USM or PZD lenses from other manufacturers. The lens exhibits good control over ghosting and flare.
Between f/4 and f/11, this lens is extremely sharp, especially in the centre. The problem though is the fact that at f/8 and f/11, it is difficult to throw the background out of focus, even if the backdrop is far from the subject. At wider apertures, it is difficult to get the entire subject sharp. In that sense, choosing the perfect aperture becomes even more critical.

Conclusion
In terms of features and build quality, one may not take this lens very seriously, but the quality is a surprise package—it produces sharp images and also controls optical aberrations quite well. Moreover, at a price of Rs. 12,990, it is really difficult to criticise this set of optics. This is, by far, the most economical macro lens available for any mount. The fact that it can also be used as a fast normal lens makes it a unique two-in-one package.

Who Should Buy It?
Alpha users who are taking their first steps into close-up and macro photography.
Why?
This is, by far, the least expensive 1:1 macro lens available in the market and still delivers efficient performance. It also doubles up as a fast normal lens.

The focal length makes this lens more suited for still subjects, and the sharpness is good. Exposure: 1/160sec at f/11 (ISO 800). Photograph/Shridhar Kunte

Final Ratings
Features
1:1 magnification, fast aperture
16/20

Performance
Excellent sharpness, minimum aberrations
32/35

Build Quality
Plastic barrel, smooth finish
20/25

Ergonomics
Lack of focus limiter switch
11/15

Warranty & Support
Wide area of service network
3/5

OVERALL: 82%
Value For Money: 4/5 stars