Thanks for the compliment Martin! I use: 70-200 2.8 IS USM (my all-time favorite) 300 4.0 IS (nice, but less quick in focussing and sharpness) 24-70 2.8 (nice, but in my opinion not supersharp) 10-22 EF-S 3.5-4.5 for special effects The 100-400 was a drama indeed. I also tried 1,4 and 2,0 convertors...