Sigma 18-35mm f/1.8 DC HSM Art Lens for Pentax

World’s first* lens offering an aperture of F1.8 throughout the zoom range. Introducing a new large-aperture APS-C format standard zoom lens. Once again, SIGMA sets a new standard.

* As of April, 2013. l Angle of view differs on cameras to which the lens is attached.

Truly a revolutionary product, the Sigma 18-35mm 1.8 DC HSM is the first wide-angle to standard zoom lens to achieve a large aperture of 1.8. Designed specifically for APS-C sized sensors, the Sigma 18-35mm 1.8 translates to 27mm-52.5mm on 35mm camera. Tapping into Sigma’s long history of lens innovations, the 18-35mm 1.8 DC HSM incorporates a wide glass molded aspherical lens with Special Low Dispersion (SLD) glass to compensate for aberrations and curvature at the widest angle. Internal focusing and zooming allows for more usability and functionality.

The 18-35mm is ideal for landscapes, portraits, still life, snap shots, casual, and close-ups and the Hyper Sonic Motor (HSM) ensures smooth, fast and accurate autofocusing. The use of Thermally Composite Material (TSC) reduces size and weight but increases the lens durability. Its new Global Vision design works with its compatibility with the Sigma USB dock for further customization. A 9 blade rounded diaphragm also creates beautiful background blur. The Sigma 18-35mm 1.8 DC HSM is a new benchmark in photographic history and a must have for every camera bag.

Image quality until now found only in a fixed focal length lens. The definitive large-aperture APS-C format standard zoom lens.

A large-aperture fixed focal length lens is great for achieving expressive bokeh effects and enjoying ultra-high optical performance. On the other hand, photographers often need to change the angle of view to properly capture the scene that presents itself. To solve this decades-long dilemma, SIGMA proudly introduces the 18-35mm F1.8 DC HSM next-generation large-aperture APS-C format standard zoom lens for digital SLR cameras. Taking on the challenge of creating the world’s first* wide-aperture lens to offer an aperture of F1.8 throughout the zoom range, SIGMA has succeeded in creating a zoom lens that offers the same high optical performance of a fixed focal length lens. These outstanding performance characteristics are especially apparent in an APS-C format camera, since it has a slightly greater depth of focus than a full-frame camera. This is a revolutionary lens that overturns preconceptions while expanding the range of photographic expression.

The full realization of the Art product concept for you to hold in your own hands and appreciate with your own eyes.

Designed with a focus on sophisticated optical performance and tremendous expressive power, our new Art line of lenses delivers top-level image quality. With unsurpassed expressive performance, these lenses reach the high standards demanded by photographers with an artistic, creative inclination. Along with landscapes, portraits, still-life, close-up and casual snaps, they’re perfect for the kind of photography that unleashes the inner artist. Ideal for studio photography, they offer just as much expressive scope when capturing architecture, starry skies, underwater shots and many other scenes.

This lens features the latest SIGMA technologies to offer F1.8  throughout the zoom range and ultimate performance

Exemplifying SIGMA’s design know-how and advanced production technologies, this innovative lens offers the highest level of craftsmanship.

To develop a large aperture zoom lens with a maximum aperture of F1.8, it was necessary to solve a variety of technical challenges. As the f-number decreases, so does the depth of focus, making it extremely difficult to minimize spherical aberration, axial chromatic aberration, astigmatism and field curvature. To minimize astigmatism across the zoom range, SIGMA leveraged its extensive experience in reducing optical aberrations and designing advanced structural elements. SIGMA gained this know-how when it developed such super wide angle zoom lenses as the SIGMA12-24mm F4.5-5.6 II DG HSM and SIGMA 8-16mm F4.5-5.6 DC HSM. Ongoing technological innovation at SIGMA’s Aizu Factory has also contributed to further enhancements in lens production. Advanced production technologies have made possible a large-diameter molded glass aspheric lens, which teams up with SLD (Special Low Dispersion) glass elements to optimize power distribution and minimize axial chromatic and spherical aberration and field curvature. Thanks to its hard-earned knowledge of lens design and advanced lens manufacturing techniques, SIGMA has succeeded in creating a lens that offers F1.8 throughout the zoom range, as well as exceptional image quality at wide open aperture.

 
Rounded diaphragm

When photographing with point light sources such as electric lights or reflections on a body of water in the background, the rounded 9-blade diaphragm helps produce an attractive bokeh effect—even at large-aperture settings.

Advanced flexibility and convenience expand photographic freedom

Covering the angles of view offered by multiple large-aperture, fixed focal length lenses, this lens combines advanced flexibility with uncompromising performance.

Zoom lenses are extremely convenient, providing a wide range of angles of view with just a twist of the zoom ring. The downside, however, is that F2.8 has been the limit of zoom lens brightness, forcing photographers to select fixed focal length lenses for brighter f-numbers. Although fixed focal lenses have been superior to zoom lenses in terms of f-number brightness and overall performance, they offer only a fixed angle of view, requiring photographers to carry several with them and change lenses as necessary. The 18-35mm F1.8 DC HSM next-generation large-aperture standard zoom lens is the world’s first* to deliver F1.8 brightness throughout the zoom range. Its bright viewfinder makes it easy to confirm focus and compose perfect shots. As compared to a F2.8 lens in the same photographic conditions, it allows the photographer to use a shutter speed that is one stop faster, reducing the influence of camera shake. In addition, the shallower depth of field makes possible a beautiful bokeh effect in the background, expanding photographic creativity. From wide open to standard apertures, this lens is highly flexible, covering the angles of view offered by multiple large-aperture, fixed focal length lenses.

* - As of April, 2013. l Angle of view differs on cameras to which the lens is attached.

An all-new, all-premium lineup

Superior functionality across the lineup, thanks to SIGMA's proprietary new A1 MTF measuring system.

There are three requirements for outstanding lenses: fine design, precise manufacturing and inspection that ensures compliance with all specifications. SIGMA lenses are born of well-thought-out design concepts and sophisticated, advanced Japanese manufacturing technology; the final clincher is our lens performance evaluation. We used to measure lens performance using conventional sensors. However, we've now developed our own A1* proprietary MTF (modulation transfer function) measuring system using 46-megapixel Foveon direct image sensors. Applying this system, we check each lens in our new lines at our Aizu factory, our sole production site. Even previously undetectable high-frequency details are now within the scope of our quality control inspections, allowing us to deliver consistently high lens performance.

*A1：Aizu １

46-megapixel Foveon direct image sensor

The 46 effective megapixel (4,800 × 3,200 × 3 layers) and 44 recording megapixel (4,704 × 3,136 × 3 layers) 23.5 × 15.7mm APS-C X3 direct image sensor captures all primary RGB colors at each and every pixel location, ensuring the capture of full and complete color. Using three silicon-embedded layers of photo detectors, stacked vertically to take advantage of silicon's ability to absorb red, green and blue light at different respective depths, it efficiently reproduces color more accurately, and offers sharper resolution, pixel for pixel, than any conventional image sensor. Since color moiré is not generated, the use of a low-pass filter is not required, meaning light and color, generated by the 46-megapixel APS-C X3 direct image sensor is captured with a three-dimensional feel.

Ultra-high precision and quality—all made in Japan

Optimizing quality with our integrated production system, SIGMA is focused on making things right, with our own hands and our own techniques. We are now one of the very few manufacturers whose products are solely "made in Japan." We like to think our products are somehow imbued with the essence of our homeland, blessed as it is with clean air and water, and focused, hard-working people. We pride ourselves on the authentic quality of SIGMA products, born of a marriage between highly attuned expertise and intelligent, advanced technology. Our sophisticated products have satisfied professionals and lovers of photography all over the world, because our manufacturing is based on genuine craftsmanship, underpinned by the passion and pride of our experts.

The finest in materials, usability and functionality

A refined, integrated design made with the photographer in mind.

All lenses in SIGMA’s new Art line come with a hood with a high-quality rubberized connector and feature a newly designed lens cap and AF/MF switch, and are designed for intuitive use and superior functionality. Inside, HSM (hypersonic motor) delivers high AF speed and extremely quiet performance. An enhanced algorithm offers even smoother automatic focusing. Full-time manual focus override is another key feature that leaves the artistic touches in the photographer’s hands. The brass mount combines high precision with rugged construction. Its treated surfaces and enhanced strength contribute to the exceptional durability of the lens. In both the external and internal parts, the optimized use of TSC (Thermally Stable Composite), an excellent match for metal parts, further contributes to the high-precision construction of the lens.

HSM (hypersonic motor)

HSM (hypersonic motor) delivers high AF speed and extremely quiet performance. An optimized algorithm offers even smoother automatic focusing, and full-time manual focus override is another key feature.

Incorporating a Inner Focus system

The lens incorporates a rear focus system that prevents focus-dependent variation in aberration, making high-level image quality possible throughout the entire image. With their unchanging barrel length, these lenses also enhance balance and stability for the photographer. Furthermore, since the front of the lens does not rotate, polarizing filters can be used with extra convenience.

TSC (Thermally Stable Composite)

A first for the industry, the barrel of the lens features a new TSC (Thermally Stable Composite) that offers minimal thermal shrinkage combined with exceptional hardness. It also offers 25% greater elasticity than polycarbonate. Since its thermal shrinkage is low, TSC matches well with metal parts, further contributing to the high-precision construction of the lens. TSC also makes possible slimmer forms for parts like zoom rings and scaling rings.

Flare and ghosting reduction

From an early stage in the lens design process, flare and ghosting have been measured to establish an optical design resistant to strong incident light sources such as backlighting. SIGMA's Super Multi-Layer Coating reduces flare and ghosting to help photographers produce sharp and high contrast images even in backlit conditions. The included lens hood can be attached to block out extraneous light, which can have a negative effect on rendering performance.

High-precision, rugged brass bayonet mount

The brass mount combines high precision with rugged construction. Its treated surfaces and enhanced strength contribute to the exceptional durability of the lens

Flare and ghosting reduction

From an early stage in the lens design process, flare and ghosting have been measured to establish an optical design resistant to strong incident light sources such as backlighting. SIGMA's Super Multi-Layer Coating reduces flare and ghosting to help photographers produce sharp and high contrast images even in backlit conditions. The included lens hood can be attached to block out extraneous light, which can have a negative effect on rendering performance.

A lens customizable to your needs

New exclusive software and SIGMA USB DOCK make customization simple.

For our new product lines, we have developed exclusive SIGMA Optimization Pro software that allows the user to update the lens firmware and adjust focus position and other parameters. The user will be able to connect the lens to a computer with a special SIGMA USB DOCK and use easy-to-operate on-screen controls to create personal lens specifications. 

 Sample Photo

What's in the box:

• Sigma 18-35mm F1.8 DC HSM Art Lens
• Front Cap LCF III 72mm
• Rear Cap LCR II
• Lens Hood LH780-06