Take a look at a more detailed look into the Canon EF 85mm f/1.8 USM
A practical and portability telephoto lens
The Canon EF 85mm f/1.8 USM produces images that are sharp and clear at all apertures. A virtually circular aperture diaphragm gives out-of-focus regions a softer, more even feel, and lets in-focus subjects stand out against a blurred background. The lens features a non-rotating front element during focusing, enabling specialist filters (such as polarisers and graduates) to be used.
Large f/1.8 aperture
A large maximum aperture of f/1.8 lets photographers shoot hand-held in difficult, low-light conditions, as well as restrict depth-of-field for creative effects.
Compressed perspective in portraiture
The short telephoto focal length of the Canon EF 85mm f/1.8 USM slightly compresses perspective, reducing the size of prominent facial features for a flattering result.
A ring-type ultrasonic motor drives autofocus extremely quickly, and in near silence. Excellent holding torque ensures the point of focus is reached accurately, without overshooting. Furthermore, full-time manual override is available, making it possible to adjust focus without leaving AF mode.
Super Spectra coating
Super Spectra coatings ensure accurate colour balance and enhance contrast. They also reduce flare and ghosting – a common problem caused by light bouncing off a camera’s sensor.
Integration with E-TTL II flash metering
The lens passes distance information back to a compatible EOS camera’s E-TTL II flash system to ensure optimal flash metering.”