The 45mm focal length provides a natural appearance, approximating how we perceive a scene with our own eyes even more naturally than a 50mm lens. It is perfect for general purpose use and could live on your Sony at all times.
It will provide optimal quality still images and video with both Sony Full Frame and APS-C image sensor cameras. For Sony APS-C camera users the lens is equivalent to approximately 67.5mm to provide an angle of view of a moderate telephoto.
Seven elements in six groups, including two Aspherical and one Extra-low Dispersion plus Ultra Multi Coating, are utilized to minimize aberrations and increase sharpness for impressive image quality.
The AF (autofocus) is optimized for quiet, fast, and precise focus detection with mirrorless cameras.
The IF (Internal Focus) design prevents both changes length and front element rotation for easy use with polarizing and other filters where positioning must be maintained.