I'm a big fan of my 100-400mm f/4.5-5.6 L IS USM lens. Its served me quite well, and better than the 400mm f/5.6 lenses I've tried from friends or other fellow photographers met out in the field. The only real detractor, however, is the aperture range...f/4.5 to f/5.6 is a bit limiting, from an AF standpoint, and from the standpoint of using a teleconverter. I'd love to have a relatively affordable telephoto zoom lens that I could slap a 1.4x TC on to get 140-560mm f/5.6, something cheaper than the new 200-400mm f/4 L IS USM.
Is a 100-400m f/4 a plausibility, for a "reasonable" cost around $3500 or so? Would it be a lens anyone else even cared about, or is that just a focal range and price that doesn't serve anyone's needs? Personally, I'd find 560/5.6 to be far more useful for general bird photography, without having to lug around a heavy 500mm or 600m L.
Thoughts?
Is a 100-400m f/4 a plausibility, for a "reasonable" cost around $3500 or so? Would it be a lens anyone else even cared about, or is that just a focal range and price that doesn't serve anyone's needs? Personally, I'd find 560/5.6 to be far more useful for general bird photography, without having to lug around a heavy 500mm or 600m L.
Thoughts?