I use the 300mm f2.8 a lot for my work and on a 1.3 crop 1dMKIV it’s often just right. I can see Canon moving to full frame 1-series cameras next year and it got me wandering whether I would need to switch to a bigger lens. 300mm is 390mm equivalent on the MKIV so I might need to start thinking of saving up for a 400mm! I was curious to see how all the new Canon Super Tele Lenses compared, and in particular where the new Canon 200-400 f4 fitted into things so I grabbed the press images and sized them all up based on the button and filter sizes.