Originally posted by Nass No, your image won't be cropped, you'll still get a full image. But, it could also cover a 35mm image fully if it were on a full frame camera. Full frame has a larger sensor area than k5 so actually you see more hence k5 is said to be cropped.
Forget about the 100/150mm thing, that's just marketing rubbish. Its a 100mm lens, but when used on apsc it has a smaller field of view than when used on 36x24. So, marketers being marketers turn that around and call it 150mm (because that also has a smaller field of view).
But fyi, a full frame lens on a k5 is actually a really good thing, because rather than using the edges of the glass which tends to be worse, you're using the centre, it's sweetspot.
while this is true, it is also true that a full frame lens is designed to project a full image circle, therefore there is a lot of stray light coming out of the rear of the lens that will be bouncing off every surface in the mirror box, reducing contrast, but also the internal baffling is designed for a wider field of view, this means there is light entering the lens that does not contribute to the image, but which could result in internal flare and lost contrast. although coatings and internal baffling are pretty good, use of a lens hood that is restricted to the FOV on digital may result in increased contrast