Incorporating Rounded Diaphragm
The 9 blade-rounded diaphragm creates an attractive blur to the out-of-focus areas of the image.
With the new product lines, supplied hoods incorporate rubber for the connected part. Lens caps and AF/MF switches are also newly designed in order to improve usability. For the parts inside, metals and a new material called TSC (Thermally Stable Composite), which works well with metals, are located to achieve products with high accuracy. The lens barrel includes the year of release, engraved for users to recognize when the lens was released.
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 MTF measuring system using conventional sensors. However, we’ve now developed our own proprietary MTF (modulation transfer function) measuringcharacteristics of digital cameras, such as compensating peripheral brightness, controlling the point images in the corners, and improving the image drawing, not only around the focusing point, but also other areas in the image.
Corresponding AF Mounts: SIGMA, Canon, Sony and Nikon