I hardly ever really test lenses, but as a service to this fine group, I have made an exception.
This is going to be a pretty big page, as it comprises 16 1000x1000 pixel details ranging from f/1.4 to f/16 for both lenses, as well as smaller full frame images (1024x683 pixel) at f/1.4, f/2.8, f/5.6 and f/11.
This is by no means definitive, it's just old Wheatfield setting up a tripod in his backyard and photographing some flowers.
I've arranged the pictures to make direct comparison by aperture value as easy as possible.
I hope this doesn't break the internet.
Please don't quote this post ad infinitum. It's just far too much bandwidth to take up if the files get repeated numerous times.
FA 50/1.4 @ 1.4
D FA* 50/1.4 @ 1.4
FA 50/1.4 @ 2
D FA* 50/1.4 @ 2
FA 50/1.4 @ 2.8
D FA* 50/1.4 @ 2.8
FA 50/1.4 @ 4
D FA* 50/1.4 @ 4
FA 50/1.4 @ 5.6
D FA* 50/1.4 @ 5.6
FA 50/1.4 @ 8
D FA* 50/1.4 @ 8
FA 50/1.4 @ 11
D FA* 50/1.4 @ 11
FA 50/1.4 @ 16
D FA* 50/1.4 @ 16
And the rendering comparisons. I jumped 2 f/stops for this.
FA50 @ 1.4
D FA50 @ 1.4
FA50 @ 2.8
D FA50 @ 2.8
FA50 @ 5.6
D FA50 @ 5.6
FA50 @ 11
D FA50 @ 11