I’m selling off some of my smaller Sigma lenses. I want to take that step up in image quality. I have decided on a Canon EF 24-105 f/4 IS L USM, a Canon EF 100-400 f/4-5.6 IS L, plus a Kenko 1.4x teleconverter. I’ll also need a 77mm circular polarizer filter at some point.

I’ll probably keep the Bigma for the time being. It is tack sharp, but unfortunately its focusing motor is slightly on the slow side for birds in flight.

For a good walk-around lens, I have chosen the EF 24-105 mm f/4 over the EF 24-70 mm f/2.8. The price of the two are almost identical, the sharpness of these two lenses are almost identical, but I hardly ever use f/2.8 for the stuff that I shoot, so the extra reach and the 3 stop IS made this a no-brainer for me.

I actually planned on getting new lenses later, but the birds’ mating season is this month – March – so either I buy new lenses right now, or I will have to wait another year.

From my experience with the Sigmas and the EOS 1D Mark IV’s AF micro adjust, I have come to the conclusion that the lenses are everything and the camera is secondary, so it will be interesting to see the (practically optimum) image quality with the L lenses.