April 19, 2013
Pool At Dawn, Shot Wide and Ultra-Wide, in Zion National Park, Utah, with the Canon TS-E 24mm f3.5 L II and TS-E 17mm f4 L

It's rare that practically the same composition will work with both the wide-angle Canon TS-E 24mm f3.5 L II lens and the ultra-wide-angle Canon TS-E 17mm f4 L lens. I made the following two images minutes apart and they show the difference in perspective provided by a 24mm lens and a 17mm lens.

I used the tilt motion on the lenses for both images to align the plane of focus from the pool in the foreground to roughly the lower edge of the sunlit portion of the hill in the background. Even though the plane of focus was near the front of the pool, the sandstone in the lower right corner was significantly higher than the pool and closer to the camera, so I had to stop down to get the whole scene in focus. f11 was sufficient for the 24mm image and f13 was required for the 17mm image.

I also used the shift motion on the lenses for both images to keep the trees vertical. One usually thinks of using shift for architectural images where vertical lines are obvious, but there are plenty of lines that should be vertical in nature too. By keeping the camera straight up and down, instead of pointing it down, vertical lines in the images remained vertical, and I effectively looked down by shifting the lens down, a little for the 24mm image and a lot in the 17mm image. If shift hadn't been used, especially for the 17mm image, the trees at the edge of the frame would be leaning significantly towards the sides of the frame which is a clear indication that a wide-angle lens was used. By keeping the trees vertical in both images, it's not evident what kind of lens was used because both look natural.