The most important features for a standard zoom lens for digital single lens reflex camera is to achieve high image quality, to meet the needs in various occasions and to be handy and compact.
The SIGMA 17-70mm F2.8-4 DC MACRO OS HSM will clear away all the general concerns, such as a short minimum focusing distance, not a long enough focal length for telephoto shooting and a small aperture value. Mainly used for general-purpose photography, this everyday lens covers a range equivalent to 25.5-105mm on a 35mm camera. It’s surprisingly compact in size for a large-aperture lens that opens up to F2.8. Great for treasured snapshots of travel or family occasions, it also handles shots that are a little bit more creative. Designed to be the kind of lens you carry around with you all the time, it delivers simplicity and is so user-friendly it’s sure to satisfy even the most demanding of users.
Main lens features:
1. Contemporary line can handle all sorts of photo opportunities
Sigma is organizing all its interchangeable lenses into three product lines; Contemporary, Art and Sports. Featuring the very latest technology, and combining optical performance with compactness, the Contemporary line covers a wide range of needs. Incorporating the very latest technology in these lenses, Sigma has solved the difficult problem of keeping size and weight low without compromising optical performance.The SIGMA 17-70mm F2.8-4 DC MACRO OS HSM is the first product from the Contemporary line. Featuring a wide zoom range, the lens has a focal range equivalent to 25.5-105mm on a 35mm lens.
2. Excellent for macro photography
This lens’ minimum focusing distance is 22cm and the maximum magnification ratio is 1:2.8. At 70mm, the working distance becomes 5.52cm. When it comes to telephoto, it can shoot pictures with a similar sensation to a macro lens. Also, without the need to change the lens, it enables photographers to take a close up pictures of subjects such as jewelry and flowers. In order to secure a clear field of view, the design of this lens is very thorough, even down to the precise position of the engraved letters on the lens.
3. 30% Smaller Than Conventional Models
For a which is used lens used in everyday situations, the small size makes a big difference. By incorporating a smaller OS unit and optimizing the structure and power distribution of optical elements, the lens barrel has now become more compact. In order to ensure high accuracy of the product, the new compound material TSC (Thermally Stable Composite), which has high affinity to metal parts, is introduced for the lens barrel. It results in better durability of the parts and smaller zoom rings and scale rings. The dimension of this lens is 30% smaller than our conventional models.
4. Superior Image Quality Throughout The Entire Zoom Range
This lens incorporates 2 FLD (“F” Low Dispersion) glass elements, which have performance equal to fluorite, 1 SLD (Special Low Dispersion) glass element and 3 aspherical glass lenses including double sided aspherical lens. By optimizing the power alignment of the lens, both chromatic aberration of magnification and axial chromatic aberration have been corrected. From infinity to macro, it achieves superior image quality through entire zoom range. This lens offers extraordinary expressive power and is capable of surpassing the requirement of the rigorous checking process of our new MTF measuring system “A1”.
5. Large maximum aperture of F2.8
The aperture value is F2.8 at the wide end (17mm), and is F4 at the telephoto end (70mm). The bright viewfinder aids focusing and composition of images. The fast apertures also offer useful functions such as fast shutter speeds to prevent an object from being blurred and ensuring a smooth bokeh in the background.
6. Optical Stabilizer
Sigma’s own unique OS (Optical Stabilizer) function is incorporated. It offers effective correction of approximately 4 stops, which makes it possible to compensate for camera shake even in macro range photography where a small blur can be easily identified.
*1. The closer the lens is to the object, the less effective the OS function is.
*2. For Sony and Pentax, OS function is not incorporated.
7. Flare and ghosting conscious design
In order to achieve high rendering on this flagship lens, flare and ghosting were thoroughly measured from an early stage to establish an optical design which is resistant to strong incident light such as backlight. The Super Multi-Layer Coating reduces flare and ghosting and provides sharp and high contrast images even in backlit conditions.
8. Incorporating Rounded Diaphragm
The 7 blade-rounded diaphragm creates an attractive blur to the out-of-focus areas of the image.
9. Hyper Sonic Motor
The HSM (Hyper Sonic Motor) ensures high speed and quiet AF as well as full-time manual focus override by rotation of the focus ring. With the enhanced AF algorithm, smoother AF is achieved.
10. Brass made bayonet mount
This lens incorporates a brass made bayonet mount which has both high accuracy and durability. A special treatment to reinforce its strength is applied to the surface giving it greater strength and making it highly resistant to long-term use.
11. Ease of use
The new product lines incorporate rubber for the attachment part of the provided lens hood. For better usability, the design of the lens cap and AF / MF changeover switch has been improved.
12. Evaluation with Sigma’s own MTF measuring system “A1”
We used to measure lens performance with MTF measuring system using conventional sensors. However, we’ve now developed our own proprietary MTF (modulation transfer function) measuring system (A1) using 46-megapixel Foveon direct image sensors. Even previously undetectable high-frequency details are now within the scope of our quality control inspections. The SIGMA 17-70mm F2.8-4 DC MACRO OS HSM will all be checked using this “A1” before they are shipped.
13. “Made in Japan”
All Sigma's manufacturing – right down to molds and parts – is carried out under an integrated production system, entirely in Japan. 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.
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