I'm a little confused about the actual focal length (and/or field of view) of the lens when attached to an APS-C sized sensor.
The Lens specifications claim that:
35MM EQUIVALENT FOCAL LENGTH WHEN USED WITH APS-C SENSOR CAMERA
Notice the 52.5 underneath. My understanding was that, by attaching a lens to a smaller sensor, the focal length would be forced up (not down). The specifications here seem to suggest that 52.5 is the lenses normal focal length, but when attached to the APS-C sensor (not full-frame), the equivalent will be 35mm.
Is it possible Sony have done some jiggery pokery on these lenses? Or have I misunderstood focal length and sensors?
Also, am I right in assuming that the focal length and the angle of view are inherently related mathematically?
Or is it just that Sony has phrased this poorly? To me, their specification sounds a lot like "The equivalent focal length of this lens, when attached to an APS-C sensor, will be 35mm.".