With the announcement of Sigma 30mm f/2.8 EX DN, along with its sister Sigma 19mm f/2.8 EX DN, Sigma Corporation has finally made its long anticipated entrance into the mirrorless lens market official. Both lenses were announced in early 2012, with the 30mm lens making its roadways to dealers in late March. The lens is available for both m4/3 as well as Sony NEX mounts and costs $199.
The optical construction of the lens consists of 7 elements in 5 groups. The build quality and finish of the lens is quite cheap - all plastic barrel with knurled plastic focusing ring. The lens is fairly small and light, measuring only 60.6x36.6mm (2.4x1,5in) and weighing only 135g (4.8pz). The lens accepts 46mm screw-in type filters and has the minimum aperture of f/22. Aperture levels are controlled electronically from the camera. The minimum focusing distance is 30cm (11.8in).
The manufacturer's box includes the lens, front and rear caps and registration card. Within the scope of this review, the lens was tested on a 16Mp and 24Mp APS-C type Sony NEX-5n and Sony NEX-7 cameras.
|Lens Composition||7 elements in 5 groups|
|Angular Field||50 degrees (Sony NEX)
|f-stop Scale||f/2.8-f/22, electronic|
|Lens Case||Soft pouch (included)
|Retail Price||$199 (2012)|
Like virtually all Sony E mount lenses, Sigma 30/2.8EX DN follows a minimalistic, bare-bone, consumer type of an approach to the design and handling. Absent are distance and DOF scales, aperture ring and lens hood. There is no built-in optical stabilization system either. To keep the price low, Sigma seems like went out of its way to use as cheap materials as possible - unlike Sony E mount lenses, which sport a lightweight aluminium finish, Sigma's lens is all plastic. But, again, short of trying to bang your lens on a rock, the lens looks and operates just fine. At the same time, the lens is about 1/3rd shorter than Sony's 30/3.5 Macro lens, making it a more compact (and faster) choice for those looking for a street-type photography.
Sigma 30/2.8 EX DN supports both AF as well as manual focusing, AF is reasonably fast, taking ~1 to 1.5 seconds to lock on target, although AF feels sluggish at times and at times noisy. Full AF in movie mode is also supported. The focusing ring does not have a limiter and rotates freely in either direction, although there is about 75 degrees of true rotational thrust for the lens to go from the infinity to the MFD. As is the case with most contrast based AF systems, Sigma would end up hunting for focus in dimly lit and low contrast environments, sometimes locking out of focus completely.