p.1 #2 · Any good Fish Eye lens suggestions for a Nikon?
Well, first I guess you have to choose focal length. Do you want a FF full-circle fisheye, a FF rectangular fisheye, or a DX rectangular fisheye? Those are the possibilities Nikon gives you. I have the 16/2.8D and it is quite good, but not amazing. The 10mm DX lens is similar in quality.
p.1 #4 · Any good Fish Eye lens suggestions for a Nikon?
There is no 10-15mm fisheye for FX, to my knowledge. There is 8mm (Nikon, Samyang/Rokinon/Walimex...), 15mm (Sigma), and 16mm (Nikon). The first are circular fisheye lenses, i.e. they make a round photo in the middle of your frame and leave the corners unused, and the latter two are rectangular fisheye lenses, i.e. they fill the frame right into the corners, but only have 180 degree coverage on the diagonals.
p.1 #5 · Any good Fish Eye lens suggestions for a Nikon?
There is the Sigma 15/2.8 FE for FX - It's supposed to be very good.
Nikon:
- 16/2.8 AF-D
- 16/2.8 AIS
- 16/3.5 AI
The 16/3.5 is by far the best of the Nikon bunch, but the 16/2.8D would likely serve you best for weddings, etc.
And, don't let anyone tell you that you don't really need to focus with a fisheye - you certainly do especially with high MP FX cameras and anything remotely up close.
I believe there are additional options that I don't know too much about.
