ahalpert
Major Contributor
But I guess you are saying, that a 17mm EFS lens looks the same as a 17mm full frame lens on the pocket 6k?
Yes, both a 17mm full-frame lens and a 17mm EF-S lens will look the same on the Pocket 6K.
A full-frame camera will record the entire image circle of a full-frame lens (or at least, a rectangular cut-out that extends to the sides)
A crop-sensor camera will record a smaller rectangular crop within that same image circle
In each case, the image circle being projected by the lens is the exact same size.
But EF-S and APS-C lenses do not project a large enough image circle to cover a full-frame sensor. If you put that lens on a full-frame camera, you will see a circular image in the middle of the frame surrounded by black.
When manufacturers report the "equivalent focal length" of a lens, they do so for the sake of photographers to make easy comparisons between lenses. If you already know what a 17mm looks like on a full-frame camera, then you know that a "17mm-equivalent" APS-C lens will produce the same field of view on the crop-sensor camera. The depth of field will be different, but you can frame the same shot.