Sigma 30mm F1.4 EX DC A-mount lens review by tthomsen
|tthomsen#4450 date: Nov-29-2008|
flare control: 5
|ownership:||I own this lens|
|compared to:||Sony SAL-1680Z Carl Zeiss Vario-Sonnar T* DT 16-80mm f/3.5-4.5|
|price paid:||390 USD (new)|
|positive:||Very high center resolution|
Very good color reproduction and contrast
|negative:||Noticeable loss of corner resolution at f2.0 and larger|
Noticeable chromatic aberration in the corners at all apertures
|comment:||My copy has on the Sony DSLR-A300 a center resolution of more than 2100 LPH from f1.4 to f8.0. The corner resolution starts at around 1400 LPH at f1.4 and is going up to 1600 LPH at f8.0. When compared to the very good Sony Carl Zeiss Vario-Sonnar T* DT 16-80mm f/3.5-4.5, the Sigma is slightly better at 30mm/f4.5, but not really that much.|
Where the lens shows mediocre performance is in chromatic aberration. It is not noticeable in the center, but is noticeable in the corners throughout the complete aperture range. I did not notice any distortion, vignetting or flare that is worth mentioning. Color and contrast are natural and quite attractive. Out-of-focus blur is, for my taste, very nice. Build-quality is excellent. Focusing is fast and accurate, even at large apertures and low-light conditions.
My first copy was actually defective, i.e. had unacceptable optical performance. Sigma acknowledged the technical defect. Since I bought the lens abroad, they required a proof that the lens was legally imported. Only then they exchanged the lens.
One practical note: The Sony DSLR-A300 does not choose aperture values lower than f2.0 in "Program" or "Auto" modes. If you want to use them, you have to switch to "Aperture" or "Manual" modes and set those values manually.
I bought this lens as a complement to my Sony Carl Zeiss Vario-Sonnar T* DT 16-80mm f/3.5-4.5 for low-light situations. The Sigma meets exactly this demand. The loss of corner resolution and the chromatic aberration in the corners are usually not that noticeable at wide-aperture shots, since those areas are usually out of focus anyways. As a result, the faults of this lens are acceptable for me. However, I would have expected a better performance in those areas from a prime lens with this price tag. Probably, Sigma put more effort into the excellent build quality than optical performance.