Sigma has introduced another very compact and lightweight 35mm zoom lens for Sony E-mount and the L-mount: The new 28-70mm F2.8 DG DN with is said to be largely based on its ART sister (24-70mm F2.8 DG DN | Art) in terms of optical design, but significantly lighter with slightly less wide angle: To be precise, it is said to weigh "only" 470 grams, making it the lightest standard zoom of its kind, according to Sigma. Just not an "Art":
The housing of the SIGMA 28-70mm F2.8 DG DN | Contemporary, for example, is said to consist mainly of lightweight components. The use of the special polycarbonate TSC (Thermally Stable Composite) is said to have a thermal shrinkage comparable to aluminium, which should ensure consistent performance even under extreme temperature fluctuations. When it comes to zoom and focus ring construction, the use of polycarbonates can seem less premium. However, Sigma assures that "the rings offer precise mechanics with an exceptionally high-quality feel."
The lens design with internal focusing consists of 16 elements in 12 groups, including 2 FLD elements, 2 SLD elements and 3 aspherical elements.
It is "compatible with high-speed autofocus stepper motors" and also provides metadata for in-camera lens-based optical correction. However, Sigma further restricts the in the fine print unspecifically: ("Function only available in combination with supporting cameras. In addition, correction capabilities may differ depending on camera model.").
It supports DMF, AF+MF and comes with a tulip-shaped lens hood. An integrated image stabiliser, on the other hand, is not found.
The SIGMA 28-70mm F2.8 DG DN | Contemporary will be available from March 2021 and will cost around 850 euros (recommended retail price).
Here is another tabular comparison of the specifications with the Art sister model: