I agree that improper use of an ultra wide zoom can become distracting and gimmicky. Personally I like to use them in situations where either the distortion is part of the creative effect or when shooting a panorama is not feasible. Some of my best shots with my Sigma 10-20 were of groups of kids tearing into birthday cake at parties and the like. For me, the FoV of an ultra wide angle lens opens up creative possibilities in much the same manner a telephoto lens does (just in a different direction).

Whatever the situation your points are valid and appreciated.

1. You should always refer to the actual lens focal length (as you do). Focal length does not change depending on the camera, even if FOV does. It just gets confusing (and is technically incorrect) to say a 50mm lens is actually 75mm on a cropped sensor camera.

2. “Consider an ultra wide angle zoom.” I am not sold on this range. Once you get past 24mm the distorted field limits possibilities to “clever” and “gimmick” shots far too much, IMO. Yes, I know these effects can be appealing, but the tricks get old fast. If one needs to capture a wider field of view, panorama software is where it’s at. Use a 28mm prime, shoot several shots horizontally and avoid perspective distortion. You’ll likely have better IQ as well.

Thanks again for these articles, which I am sure are especially helpful to beginners.

I would defer to the 300mm f/2.8 over the 400 though. It is lighter and easier to carry and is the sharpest telephoto Canon makes. (The Nikon 300 /2.8 is also wicked sharp) I would also add a 1.4x tele-convter to this list. This makes the 300 a 420mm f/4. You can also use it with the 70-200 /2.8. You do loose on stop of aperture and a little sharpness but both lenses are so sharp to start with that it makes it worth while. For under $300 it’s like getting another lens in the bag minus the extra weight and space.