close to fixed focal length lens.
Incorporation of focus limiter
Excellent usability is achieved by incorporating inner focusing and zooming that requires no change in the length of the lens for focus and zoom. It is possible to use with a rounded filter, such as a Circular Polarizer, as the front part of the lens is fixed. Due to the focus limiter offering adjustable range of auto focusing, this lens can provide fast focus setting. The USB dock enables users to change the range of the auto focusing at the discretion of users' creativity.
Ease of use
Many parts of this lens have been designed for comfortable usage. For example, the design of the zoom ring is concerned with a texture when you hold it, the position of printed letters and the 4 control switches with integration-considered shape of the screws. Included accessories such as the removable lens hood and the newly designed tripod collar with strap ensure added ease of use.
Newly developed "USB DOCK" exclusively for new product lines
Based on these new lines, we have developed special software (SIGMA Optimization Pro) that can update the lens firmware and adjust parameters such as focus. In addition, the lenses from our Sports line have customizable AF speed, focus limiter and OS function. The "Custom Mode Switch" is the device for further customization on the dedicated lenses.
Flare and ghosting conscious design
SIGMA's Super Multi-Layer Coating reduces flare and ghosting. It provides sharp and high contrast images throughout the entire zoom range.
Excellent in handheld photography for telephoto shooting
This lens incorporates the OS system which offers the use of shutter speeds approximately 4 stops slower than would otherwise be possible, ensuring the excellent use in handheld photography for telephoto shooting. The OS system has two modes - OS mode 1 is suitable for general photography, and OS mode 2 is best for panning shots of subjects such as planes or racing cars. It is possible to adjust the OS using the optional USB DOCK.
Quiet and Fast AF
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. The full time manual, which offers further adjustment after focusing with AF mode, is possible. By using USB Dock, you can change and adjust the AF speed at your convenience.
Incorporating Rounded Diaphragm
The 9 blade-rounded diaphragm creates an attractive blur to the out-of-focus areas of the image.
APO Tele-Converter (Optional)
The addition of Sigma's 1.4x EX DG APO or 2x EX DG APO TELE CONVERTER produces a 168-420mm F4 AF telephoto zoom lens or a 240-600mm F5.6 AF telephoto zoom lens respectively.
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.
Evaluation with Sigma's own MTF measuring system "A1"
We used to measure lens performance with an 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.
"Made in Japan"
All Sigma's manufacturing - right down to the 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.