Originally posted by Docrwm There are quite a few threads on this precise comparison. Many believe that the 1.7 is better in sharpness and IQ. I disagree with them and always point out that the 1.7 has a very recessed front element and the 1.4's is very exposed, so the 1.4 MUST have a hood to perform decently. The other issue for me is that the 1.4 is still in production and is faster.
I agree!
I've had 5 versions of the 1.7 (2M,2A,1 F) and 5 different 1.4s (S-M-C, SMC, K, M, FA), plus 3 different 55/1.8s and used with a hood, and also in a non scientific but controlled test, they all performed (for me) so close to the same that it was/is near impossible to see a difference IMHO.
For me, there's one major difference and that is the (most) 50/1.4s have an eight blade diaphram and the 1.7s and 1.8s have six. I much prefer the bokeh when stopped down from the 1.4s.