I take a lot of pictures of airplanes. It's sort of like bird photography, but the birds are big and move very predictably. I went through a long process of trying to find a lens I liked for this purpose...the Canon 100-400 L is generally considered the best lens for this purpose. I've rented it a couple of times, but I don't like it...the push-pull zoom isn't intuitive for me, and the image quality is good but I've seen better.


So I got a great deal on a used Sigma 100-300 f/4 a few months ago. I absolutely love it. It has a zoom ring (with internal zoom!) and constant aperture, focuses quickly and accurately on my 40D, and is sharper than the 100-400 at shared focal lengths and apertures, and takes a teleconverter reasonably well.


Does anyone else use this lens and have either good or bad opinions on it? It doesn't seem to be very popular, which kind of surprises me... Bryan, any chance of a review? It fits into the "no first-party equivalent available" category.