Here is the 50mm prime and premium lens in Sony Alpha lenses: the Zeiss Planar T * 50mm F1.4 ZA SSM. This fast prime lens is quite upscale and is compatible with Full Frame DSLR and APS-C DSLRs in Sony A mount.
This is a very nice piece of glass that Sony announced today with this Zeiss Planar T* 50mm F1.4 ZA SSM. It is compatible with digital SLRs equipped with sensors such as the 24 x 36 SLT-A900 for example, as with other APS-C DSLRs (see the Sony slt-A58 announced today, for example). Mounted on an APS-C body this 50mm lens becomes a luxury portrait lens of 75mm F/1.4. The diaphragm has 9 circular blades and its closest focus is 45 cm from the subject. Its optical built mobilizes 8 lenses gathered into 5 groups and 2 aspherical lenses. The Zeiss Planar T* 50mm F1.4 weights 640 grs and will cost around $1,500… Prime lens and premium lens !
Of course as suggested by the T*, this lens gets the famous Carl Zeiss coating which improved contrast and sharpness while fighting against flare and ghosting.