Just for fun, I shot a quick comparison of the Nikon 50mm f/1.8 on the D800 against the Fujinon 35mm f/1.4 and the Fujinon 18-55mm f/2.8-4.
Below are the three images I took – all shot at f/5.6 1/60th ISO 200 with a Nikon SB900 set at 1/32nd in manual mode. All are jpegs straight out of the camera. By shooting jpeg, you get the basic camera lens correction for each one. I didn’t want to shoot RAW because I didn’t want any of my own processing to get in the way, and it just adds an extra layer of complication. The D800 file has been downsized to 16Mpx to match the Fuji files. Do click on the images to see larger versions.
Nikon D800 + 50mm f/1.8
Fujinon XF 18-55mm f/2.8-4
Fujinon 35mm f/1.4
Here are the 1:1 (100%) comparisons.
Nikon 50mm 1.8 v Fujinon 35mm f/1.4
Nikon 50mm 1.8 v Fujinon 18-55mm f/2.8-4
Fujinon 18-55mm f/2.8-4 v Fujinon 35mm f/1.4
The 18-55 is the weakest, as you might expect, but to be honest unless you look at a 2:1 view they are a lot closer than you might think – and who views images at 2:1 (200%) in the real world anyway!
I only did this for a bit of fun and interest, so it was just a quick test and by no means scientific or even pretending to be comprehensive, but I think it shows how well the 18-55mm Fujinon lens holds up against two other very well respected lenses. As a final note, I don’t know what you think, but I reckon the Fujinon 35mm on the X-Pro1 beats the Nikon 50mm on the D800!