The Sony Zeiss Sonnar T* FE 55mm f1.8 ZA is a prime lens for full-frame mirrorless cameras with Sony E mount. It is also designated "SEL55F18Z". The lens was created from a collaboration between Sony and Carl Zeiss and was launched in 2013 together with the first full-frame cameras of the A7 series.
It covers a slightly extended normal range and offers a maximum aperture of f1.8. With its angle of view compared to traditional 50mm lenses, the optic is suitable for portraits, street photography, product shots, and general everyday use.
The optical system is based on the Sonnar design from Carl Zeiss. This construction was developed for a compact form factor with reduced internal glass surfaces. The interior comprises 7 lens elements arranged in 5 groups. These include 3 aspherical elements that compensate for aberrations such as spherical aberrations.
The T* multi-coating reduces reflections, stray light, and ghosting when shooting against direct light sources. The aperture mechanism uses 9 rounded blades and allows stepless adjustment of the aperture from f1.8 to f22.
The outer housing is made of an aluminum alloy and is sealed against the ingress of dust and moisture. With a weight of 281 grams and a length of 70.5 millimeters, the construction remains lightweight and well-balanced on compact bodies. The filter diameter is 49 millimeters.
A built-in linear autofocus motor moves the internal lens groups quietly and directly. This supports automated focusing in both photo and video recording. The lens does not include its own optical image stabilizer, as the camera system relies on in-body image stabilization.
The optic can be used on cameras with full-frame sensors as well as on models with APS-C sensors. When used on cameras with a smaller sensor, the crop factor results in an effective angle of view equivalent to approximately 82.5 millimeters in full-frame equivalent.
