400/4 = 100 mm front ø (no, it's aperture ø )
500/5.6 = 89 mm front ø (dito)
11% less glass? I know, it's oversimplified, and Nikon uses more lightweight plastics where Canon relies on magnesium. It's just: The old 300/4 was 1440 grams, the new 300/4 PF is 755. No matter what - it certainly would add enough coins to the bill that the weight reduction is even more massive - at least the one in the purse.
500/5.6 = 89 mm front ø (dito)
11% less glass? I know, it's oversimplified, and Nikon uses more lightweight plastics where Canon relies on magnesium. It's just: The old 300/4 was 1440 grams, the new 300/4 PF is 755. No matter what - it certainly would add enough coins to the bill that the weight reduction is even more massive - at least the one in the purse.