For a frame of reference, we also tried the lens on a 7D body. With the zooming limiter turned off, you can go all the way to 8mm, which gives you an image with cropped off corners. The amount of the image gets lost actually seemed to be a bit less than we originally expected. When the limiter switch (which is located on the right of the lens barrel) is turned on, the ring stops turning at 10mm, assuring a full-frame image. Obviously, the fisheye effect wasn't quite as pronounced on a crop sensor body—you lose those outside areas where the most distortion happens--but, even at 15mm (24mm equivalent), it's still very clear that you're shooting with a fisheye. We did some A/B with a non-fish 17-40mm f/4L just for reference and the difference is extremely noticeable.