Actually it makes a lot of sense. When the 2-4 came on the scene the 100-400 II was nowhere to be seen. The 1-4 is quite versatile, offers amazing close focus that increases its versatility–see today’s featured image for example, is far lighter, and cost a fraction of what the 200-400 costs.

The huge advantage of the 200-400 is the larger aperture: f/4 as compared to f/5.6 (and f/5.6 versus f/8 with a 1.4X TC in place with either lens). That especially in the low light conditions that you often encounter in the Southern Ocean locations: The Falklands, South Georgia, and Antarctica.

An f/4 lens gives folks with the 200-400 all AF points at f/5.6 with current camera bodies and the internal TC engaged. At 560mm you are limited to the center AF point plus the four assist points in Expand. And as mentioned above, the 2-4 with its built-in TC has a big advantage in arid, dusty situations.

The law of supply and demand is relentless. With more and more folks going to the 100-400 II there are more 200-400s for sale. artie

Hey Doug, You are correct sir. artie