Despite its small size, no compromise has been made on the optical performance of the SIGMA I series 24mm F3.5 DG DN | Contemporary. It is capable of capturing the finest details when shooting on high resolution full-frame cameras, and it does so across the entire frame, which means photographers can rely on edge-to-edge sharpness at all apertures when shooting wide-angle scenes.

The lens features the latest optical design optimised for mirrorless systems. This includes three high-precision, glass-molded aspherical elements created with advanced processing technology, and SLD glass and high refractive index glass elements. Together they make it possible to combine performance with portability. In addition, the smooth focus drive system designed around a quiet and fast stepping motor also makes the I series 24mm F3.5 DG DN | C a desirable choice for shooting video.

The lens renders very attractive bokeh, and out-of-focus highlights are near-circular, even at the edges of the frame. This is a particularly useful characteristic when shooting close-ups at the lens’ exceptionally close focusing distance of 10.8cm, where the subject is sharp and the background is blurred due to a shallow depth-of-field. The maximum reproduction ratio is 1:2.

The SIGMA I series features full-frame-compatible lenses that offer mirrorless users a new and better alternative, both in the experience of shooting with the lens and in the impressive results it is able to achieve. One of the key advantages of mirrorless cameras is their smaller form-factor, and this new 24mm optic is designed to be perfectly matched to these more compact systems without sacrificing performance. This combination of superb optical quality with exceptional portability, not previously possible with DSLR systems, will bring new opportunities to this and future generations of photographers.

Simultaneously, SIGMA is aware that, in this day and age when we have such huge diversity when it comes to what we use to photograph, as represented by smartphones, people look for something more than a mere act of taking pictures when they choose to own a camera and lenses. SIGMA’s excellence in development and processing technologies has been built up since its founding in 1961, and has become further sophisticated with the introduction of the SIGMA Global Vision range in 2012. With this as a base, SIGMA has given careful thought to how photographers use and enjoy their lenses, including optical design, advanced functionality, superb build quality and the experience of picking up and using the lens, and with all of this carefully considered, the I series was born.

Sigma is now one of the very few imaging manufacturers whose products are solely made in Japan. This gives us full control over our production processes and helps us maintain the highest levels of quality control over the design, manufacture and construction of every product. Great care is taken to ensure the highest quality materials are chosen.

All I series lenses are designed with an all-metal barrel. The precision-cut aluminium parts not only give the lens a sleek, stylish finish but provide superb durability, which improves the quality of the entire product. Metal materials are also used in internal structures that slide with the operation ring for added robustness. These high-precision components, crafted with Sigma’s cutting-edge metalworking technology, are also used in the production of the cine lens line-up for professional film-makers.

The lens has an aperture ring so that users can change aperture using either the lens or the camera. Great attention was paid to ensure the click is well-define but not too sharp. Sound-deadening grease has been used to create a more rounded sound. Similarly the metal focus ring is perfectly weighted for a precise and smooth action to ensure accurate manual focus control. The ‘knurling’ grooves cut into both rings improve slip resistance.

Many photographers will choose to pair the 24mm F3.5 DG DN |C with the 45mm F2.8 DG DN | C (see right). Not only do they share the same filter size of 55mm but they have a matching outermost diameter and similar overall lengths. With a combined weight of only 440g (figure for L-Mount) these two lenses provide plenty of shooting options and are easily light enough to carry around all day.

The 24mm F3.5 DG DN | C comes with a carefully machined metal lens hood, a feature not even found on Sigma’s Art series lenses. A large number of grooves called ‘knurling’ are cut in, improving the lens operation by serving as slip resistance and giving the lens a premium look and feel unique to the I Series. A specially chosen plastic was used for the part that connects to the lens to ensure smooth operation.

Included in the box is the regular Sigma plastic lens cap as well as an all-metal magnetic cap (pictured left), which snaps firmly on to the end of the lens. With no requirement for a spring-loaded clasp, the cap has a sleek, minimal finish.

Available to buy separately is a new lens cap holder, onto which the magnetic metal lens cap can be quickly and easily attached when the lens is in use. This keeps the cap within easy reach and makes it less likely to get lost. Plus, its elegant design is a stylish addition to a photographer’s equipment.

The holder comes with a carabiner so that it can be attached to clothing or a bag strap.