Sigma has announced a pair of lenses in its 'I-series' of premium compact primes: the 24mm F2 DG DN 'Contemporary' and 90mm F2.8 DG DN 'Contemporary'. The lenses, designed for E- and L-mount bodies, are all-metal and feature aperture rings and weather-sealing. Both will be available later this month for $639.

The 24mm F2 DG DN has 13 elements in 11 groups, including two aspherical elements. One FLD ('F' low dispersion, similar in low dispersion and low refractive index characteristics to fluorite glass) and two SLD ('special low dispersion') elements help suppress chromatic aberrations. A 'Super Multi-layer' coating reduces flare and ghosting. The lens' focus group is quietly driven by a stepping motor.

The minimum focus distance on the 24mm is 0.25m (9.7"), while the maximum magnification comes in at 0.15x. The lens dimensions are 70x72mm for the L-mount version and 70x74mm for E-mount. They weigh 365g (12.9oz) and 360 grams (12.7oz), respectively.

The lens comes bundled with a metal hood, and both pinch-type and magnetic lens caps. The lens is threaded for 62mm filters.

The 90mm F2.8 DG DN is a bit smaller than the 24mm, but it's also a stop slower. It has a total of 11 elements, including one aspherical and five SLD elements. As with the 24mm F2, a stepping motor is used to drive the focus unit on the 90mm.

The minimum focus distance on this lens is 0.5m (19.7"), with a maximum magnification of 0.2x. The dimensions of the 90mm are 64x60mm for L-mount and 64x62mm for E-mount. Both weigh just 295 grams (10.4 ounces). The 90mm uses 55mm filters.

As mentioned above, both lenses will be available in September for $639.

Sigma 24mm F2 DG DN / 90mm F2.8 DG DN specifications

 Sigma 24mm F2 DG DN | CSigma 90mm F2.8 DG DN | C
Principal specifications
Lens typePrime lens
Max Format size35mm FF
Focal length24 mm90 mm
Image stabilizationNo
Lens mountL-Mount, Sony FE
Aperture
Maximum apertureF2F2.8
Minimum apertureF22
Aperture ringYes
Number of diaphragm blades9
Optics
Elements1311
Groups1110
Special elements / coatings1 FLD + 2 SLD + 2 aspherical elements1 aspherical + 5 ED elements
Focus
Minimum focus0.25 m (9.84)0.50 m (19.69)
Maximum magnification0.15×0.2×
AutofocusYes
Motor typeStepper motor
Full time manualYes
Focus methodInternal
Distance scaleNo
DoF scaleNo
Focus distance limiterNo
Physical
Weight365 g (0.80 lb)295 g (0.65 lb)
Diameter70 mm (2.76)64 mm (2.52)
Length72 mm (2.83)60 mm (2.36)
MaterialsMagnesium alloy
SealingYes
ColourBlack
Filter thread62 mm55 mm
Hood suppliedYes