I have just obtained my first FX digital, and I read somewhere about cutting off the hood of the 10.5mm f/2.8 Nikkor so it would be more acceptable on the FX format. So, I did just that, and it is a stunning lens. Some additional trimming is required on my first attempt, but here is a full size file on Flicker which blows my mind. This is an incredibly sharp lens. Look and see what I mean. Dpeth of field is immense of course. Exposure data: ISO 1600 1/160 at f/5.0 NIIKON D4
So, to modify, one puts a file card inside the hood, around the perimeter of the lens and tapes this to the hood. This protects the surface from debris while cutting. Next, mark a line around the lens hood at the point at which the short and long sides of the hood meet, closest to the lens surface. Cut on this line. There are many saws, I used a high speed cutting tool initially, being careful to not cut through and hit the lens surface. The hood is plastic, so it "melts" when using a tool of this type. Once the hood comes off, finish up with a file, being extremely careful to not touch the lens surface.
This modification is not for the faint of heart. If you scratch the lens, it is trash. But as the results above show... pretty cool!