After yesterday's announcement from Nikon of a 18-300mm f/3.5-5.6 ED VR lens at $999/£850, rival lens maker Sigma has announced a new 18-250mm f/3.5-5.6 zoom (actually an update) featuring offering many of the same features; optical image stabilization (unfortunately not included for Sony and Pentax as the bodies don't support OIS), ultrasonic focus motor, low dispersion glass and aspherical elements for nearly half the price, $TBA / £499. The lens focuses down to 35cm (45cm for the Nikkor) and weighs just 470g as opposed to 830g. The downside? Well it doesn't have quite the same reach (250mm vs 300mm) and it doesn't have sealing around the lens mount, but on paper at least these two lenses are very similar. We'll have to see how they perform optically.
The Sigma Corporation is pleased to announce the announce the new Sigma 18-250mm F3.5-6.3 DC MACRO OS HSM, a compact, high zoom ratio lens, covering wide angle, telephoto and macro photography.
By revolutionizing the optical and structural design of the Sigma 18-250mm F3.5-6.3 DC OS HSM, this new lens achieves a compact size and a minimum focusing distance of 35cm. Sigma’s newly developed material, Thermally Stable Composite (TSC), which maintains its size and structure in varying temperatures, is incorporated into the lens barrel.
Designed exclusively for digital SLR cameras, this versatile lens covers wide-angle to telephoto making it suitable for many types of photography. Its small size and huge focal-range make it perfect for travel photographers and those who like to keep equipment down to a minimum.
This is the first lens to use Thermally Stable Composite (TSC). This is a unique product that’s been developed in conjunction with a specialist manufacturer. This material is unique to Sigma and has metal like characteristics. Traditionally, Sigma use engineering plastic which is polycarbonate mixed with 20-30% glass. The advantages of this are its high resistance to impact, it’s lightweight and it doesn’t degrade over time. However, the drawbacks are its plastic feel and high dependency on temperature. In differing temperatures it expands and contracts considerably. As a result, a large gap is required between any metal/composite interface to allow for this expansion/contraction in size. The new TSC material has overcome this and is much more stable in varying temperatures. Consequently, a tighter construction can be achieved with thinner and lighter material.
Sigma’s own unique Optical Stabilizer (OS) function is incorporated into this lens. It offers effective correction of approximately 4 stops, overcoming camera shake even in close-up range photography.
※Sony and Pentax mounts are not incorporated with OS function.
One SLD (Special Low Dispersion) glass element offers excellent correction of color aberration and three aspherical lenses, including a double-sided aspherical lens, prevent and correct all types of aberrations such as astigmatism, achieving high image quality throughout the entire zoom range. Sigma’s Super Multi-Layer Coating reduces flare and ghosting, ensuring sharp and high contrast images even in backlit conditions. The supplied petal-type hood can be attached to block out extraneous light which has a harmful influence on image rendering.
The close-up capability is improved with a minimum focusing distance of just 35cm throughout the entire zoom range and maximum magnification ratio of 1:2.9. When the APS-C size sensor is taken into consideration, the effective maximum reproduction ratio becomes 1:2.
The lens benefits from a Hyper Sonic Motor (HSM) to ensures fast and quiet auto-focusing.
This lens incorporates a brass made bayonet mount which has both high accuracy and solidity, the same as the mount of camera bodies. A special treatment to reinforce the strength is applied to the surface to ensure resistance to wear through long-term use.
*Sony and Pentax mounts do not incorporate Optical Stabilisation.
Minimum Aperture F22
Minimum Focusing Distance 35cm
Lens Construction 16 Elements in 13 Groups
Maximum Magnification 1:2.9
Angle of View 76.5°- 6.5°
Filter Size 62mm
No. of Diaphragm Blades 7 pcs (Rounded)
Lens Hood Petal-type
Dimensions Diameter 73.5mm x Length 88.6mm
Available Fittings Sigma AF, Nikon AF, Canon AF, Pentax AF, Sony AF