After the official preannouncement of the new Sigma 18-35mm f/1.8 DC HSM lens, the first unofficial image samples have already started to appear on the web.
Aimed at cropped sensor cameras (the DC acronym in the name stands for Digital Crop), the new Sigma lens is the first one to exhibit f/1.8 constant aperture in a zoom lens. You can already check some sample images taken with the Sigma zoom lens, mounted on a Canon EOS 600D body, in one preview from lcap.tistory.com .
Vignetting, distortion, light fall-off and sharpness samples
For testing purposes, the same Korean website shows the amount of vignetting when mounting the Sigma lens on Canon 5D Mark II full-frame DSLR. Of course, a dedicated version of the Sigma lens will be available for Nikon (DX) DSLRs too.
Distortion and light fall-off images are also presented, but the ones that reflect the level of sharpness at f/1.8 aperture throughout the focal range are of particular interest. The details seem satisfying enough (for this opening), but we really don’t know the amount of sharpening applied (if any) in post-processing of those samples. Nevertheless, Sigma has shown some strong results regarding sharpness in its latest lens iterations.
Another member of Sigma Art lens category
Back in autumn 2012, Sigma announced a reorganization of its lens lineup, dividing all future lenses in only three categories: Contemporary, Art and Sports. Sigma Art lenses were defined as follows:
“These lenses are developed with an emphasis on artistic touch and are designed to meet the expectations of users who value a creative, dramatic outcome. Along with landscapes, portraits, still-life, close-up and casual snaps, these lenses are perfect for the kind of photography that unleashes the inner artist”.
The spectacular Sigma 35mm F1.4 DG HSM (reviews: here, here and here) was the first lens from the Japanese manufacturer’s new Art category. It can be found at Amazon for $899. The price of the newly introduced Sigma 18-35mm constant aperture zoom lens – included in the same Art category – is still unknown at the moment, but, looking at the spec sheet, it won’t come cheap.
Why so much interest surrounds this lens
Although the focal range is a little bit limited – Sigma 18-35 mm f1/.8 has an angle of view equivalent to a full-frame lens of 27-52.5 mm – it is the first zoom lens for cropped DSLRs that can obtain the same depth of field (DOF) as a full-frame zoom lens @ f/2.8 mounted on a full-frame camera. So, with a cropped DSLR from Canon or Nikon, paired with this lens, you could obtain the same shallow depth of field as a 24-70mm @ f/2.8 midrange zoom lens mounted on a full-frame camera (sure, Sigma has shorter “equivalent” focal range at both sides, but nevertheless this is an accomplishment).
Here are the specifications for Sigma 18-35 mm f/1.8 DC HSM lens:
|Lens Construction||13 elements in 11 groups|
|Filter size||φ 67 mm|
|Angle of view (35mm equivalent)||63.4°|
|Minimum focusing distance||30cm / 11.8in|
|Dimensions (Diameter x Length)||φ 77 mm x 94.0 mm / 3.0 in x 3.7 in|
|Number of diaphragm blades||9 (Rounded diaphragm)|
|Maximum magnification ratio||1：5.2|
Unexplored niches speculated by third party lens manufacturers
The quality of third party lenses has improved in the last few years. Moreover, manufacturers like Sigma, Tamron and Tokina are now exploring not only the market of inexpensive lenses, but also lucrative niche markets not yet considered by first party manufacturers like Canon, Nikon or Sony. Last year, Tamron was the first manufacturer to launch a fast constant-aperture full-frame midrange zoom lens with vibration reduction technology (Tamron SP 24-70mm Di VC USD, available on Amazon for $1299). Now, Sigma is the first lens maker to come up with an f/1.8 constant aperture zoom lens for cropped DSLRs.
It seems that those third party Japanese manufacturers are more eager to innovate in order to gain market share. Time will tell if their tactic will pay off in the long run.