Sigma has a long history as a lens maker, having been founded over l years agone. In the film era it was all-time known for relatively inexpensive lenses that undercut the photographic camera makers' own equivalents in terms of price. But this has changed over the part decade or and so; while other companies accept shifted manufacturing to cheaper locations such equally People's republic of china and Thailand, Sigma has stubbornly refused to move from its factory in Aizu, Japan. This means it can no longer compete in the same fashion on price alone, and it's therefore switched its focus towards higher-value offerings.

Over the by few years nosotros've seen increasingly ambitious concepts appear from the company's design studios. The original (and recently-replaced) 30mm F1.4 EX DC HSM has long been ane of our favourite lenses for APS-C SLRs, and the 50mm F1.4 EX DG HSM grabbed our attention back in 2008 due to its sharpness at large apertures. Virtually recently the 35mm F1.4 DG HSM impressed united states with its exceptional optical quality at a very competitive price. This all bodes well for the company'due south latest offering - the record-breaking eighteen-35mm F1.8 DC HSM, which is the first constant F1.viii SLR zoom lens to hit the market.

Sigma'due south choice of F1.viii as maximum aperture isn't a coincidence; it ways that the lens will offer the aforementioned control over depth of field as an F2.eight zoom does on full frame. What'southward more, combined with an APS-C sensor, the system will also offer finer the same calorie-free-gathering capability as an F2.eight lens on total frame. By this we mean that it will exist able to project an image that's merely over twice as bright onto a sensor that's slightly less than half the area, significant the aforementioned total corporeality of light is used to capture the paradigm. This is important every bit it'south a major determinant of image quality. Essentially it means that APS-C shooters will be able to apply lower ISOs when shooting broad open in low lite and get similar levels of image noise, substantially negating i of the primal advantages of switching to full frame.

As we'd expect at this level, the lens uses an ultrasonic autofocus motor for fast, silent focusing. It's compatible with Sigma'southward new USB dock which allows you to fine-melody autofocus behaviour in much more than detail than the AF microadjust corrections found on SLRs, which should help go the best possible focus accuracy and make the almost of the big aperture. It also incorporates several of the thoughtful design touches that nosotros were impressed past on the 35mm F1.4, including an improved AF switch, and a large grip area on the base of operations of the barrel for better handling.

The lens'due south 27-53mm equivalent focal length range is obviously a piddling limited, but should nevertheless be rather useful for such applications equally wedding and events photography. Then while it may not quite match the capabilities of a 24-70mm F2.8 on a total frame SLR, for existing APS-C users it should offer something very close. Crucially, at a street price of around $800 / £650 at the time of writing, for existing APS-C shooters it's an awful lot cheaper than buying a 24-70mm F2.viii and a total frame SLR to go with information technology.

Overall the 18-35mm F1.8 is a really intriguing product, and nosotros applaud Sigma for pushing the boundaries of lens design ahead of the more conservative camera manufacturers. But can an F1.8 zoom really deliver proficient results? Let's find out.

Headline features

  • xviii-35mm focal length (approx 28-50mm equivalent)
  • Extremely fast F1.8 maximum aperture
  • Ring-blazon ultrasonic focus motor with total-time transmission override
  • Initially available in Canon EF, Nikon F and Sigma SA mounts; Pentax K and Sony Alpha to follow

Angle of view

The pictures below illustrate the focal length range from wide to telephoto (on Canon APS-C, 1.6x). The 18-35mm covers a modest 2x zoom range.

18mm (29mm equivalent) 35mm (56mm equivalent)

Sigma eighteen-35mm F1.8 DC HSM specifications

 Engagement introduced  April 2013
 Street Price (August 2013)  • $800 (United states)
• £650 (Britain)
• €850 (EU)
 Maximum format size  APS-C
 Focal length  18-35mm
 35mm equivalent focal length (APS-C)  • 27-53mm (1.5x)
• 29-56mm (Canon i.6x)
 Diagonal angle of view  76.5° - 44.2°
 Maximum aperture  F1.8
 Minimum aperture  F16
 Lens Structure  • 17 elements in 12 groups
• v SLD drinking glass elements
• four glassmold aspherical elements
 Number of diaphragm blades  9, rounded
 Minimum focus  0.28m / 0.92ft
 Maximum magnification  0.23x
 AF motor type  • Ring-type Ultrasonic Motor
• Full time manual focus
 Focus method  Internal
 Zoom method  Rotary, internal
 Image stabilization  No
 Filter thread  • 72mm
• Does non rotate on focus
 Supplied accessories*  • Front and rear caps
• Lens hood LH780-03
 Weight  810g (28.6 oz)
 Dimensions  78mm bore 10 121mm length
(3.ane ten four.8 in)
 Lens Mount  Canon EF, Nikon F, Pentax K, Sigma SA, Sony A

* Supplied accessories may differ in each country or area