Panoramic Photography ~ Shaving the Nikon 10.5mm fisheye!
If you are reading this page, you probably fall into one of two categories.
1/ You've been hunting for a tutorial regarding this subject on the web and are now chuffed to bits
that you've stumbled accross this page packed full of advice.
2/ You are wondering why on earth anyone in their right mind would want to "shave" a fisheye lens and are reading this
article with incredulity.
The reason for shaving the 10.5mm Nikkor DX is so that it can be attached to a full-frame camera (such as the D700 or Canon 5D II) and the photographer can take advantage of the extra
field of view granted by a full-frame sensor. Under normal circumstances if you attach this DX fisheye lens to a Nikon full-frame camera, one of two things happen. Either the camera automatically
goes into DX mode and crops the image to the center of the frame (reducing the image to 5.1 megapixel on a D700) or the user manually sets the camera to FX mode and the image takes up
the whole frame. However, in the second instance the image has a dark border around the edge where the lens' sun visor encroaches on to the new enourmous fov.
This means that the fov is not much larger than if the camera was still in DX mode.
So what are we going to do about it? If you are feeling rather timid you could grumble a bit, remove the lens from the camera and then put it back on e-bay where you probably bought it in the first place. If you're a bit braver (and the sensible type) you might hunt around for a Nikon Service store that will agree to carry out the required surgery for you (at a hefty fee). But if you want to take pictures with this lens TODAY, well, what the heck let's go into the workshed and dig out that hack-saw!
How to saw up a £500 Nikon lens
At last, you've made your decision. If you've reached this far down the page, I'm assuming that you're opting for the amputation - Congratulations! In about an hour's time you'll be taking shots with the most incredible fov you can imagine (or crying over a shattered piece of glass). Seriously though, here is the procedure broken down into easy chunks.
Gather together the neccesary equipment. You will need a hack-saw with a sharp blade, a sharpened pencil, a chordless drill and some paper.
Firstly you need to decide where to make your cut and then mark a line. This is best done by securing the pencil and then rotating the lens against the pencil tip as illustrated. I cut mine approx
1 to 1.5mm below the visor indents. Go as close to the indent as you dare. Once you have marked your line, set the manual focus dial to minimum. THIS IS VERY IMPORTANT! By doing this you will
be extending the lens outwards away from your cut-line. 
That way when your saw comes out the other side of the plastic, it will not be anywhere near the glass. Put some tape around the inside of your cut line.
This will secure the focus ring and also protect from any wayward saw movements. Now place your paper around the inside of the visor - you can jam it down the side of the lens but don't be tempted to push it too far in
as you may have trouble retrieving any bits that get left behind during the cutting. That's it, you're ready to start the exciting bit!
Slowly Does It
The main advice I have when you begin the actual cutting is TAKE IT SLOWLY. In fact, take as long as you want, there's no rush. Begin by carefully going around with the saw and cutting a groove on your cut line. Don't try to saw all of the way through at this stage, just create that groove all of the way round concentrating on getting it lined up neatly with your pencil line. Once you have gone all of the way around, repeat this procedure again so that your groove is a bit deeper. Keep repeating this until you start to feel the saw going through the other side of the plastic. You will be able to see the white paper through your cut when you have gone far enough (you will also be able to feel the metal underneath against the saw). This is when you need to be especially careful.
Once you have cut far enough, the visor should simply start to pull away, if it doesn't then you haven't cut far enough. Pull all of the cut plastic away and.......... hey, presto, your new lens is born! 
You may find as I did that some small pieces of paper are left
down the side of the visor's new edge. If this is the case, the focal ring may be a bit stiff so be careful when you set the focus back to infinity.
Finally, it is a good idea to tape up the focal ring. This will stop the focus from being accidentally adjusted, but will also stop the lens cover from bashing into the glass if pushed on too far. Mount the lens back onto your full-frame camera and the results are astounding. Now you realise it was worth all of the effort! The picture of my kitchen below shows the new field of view. Taken at 0 degrees (portrait mode) you can see most of the tripod head. The light at the top of the picture was directly above the tripod so you can see that the fov is now way beyond 180 degrees. Four shots around will stitch together smoothly with PTGui generating the control points automatically. There is no need for a zenith or nadir shot. It is also possible to get away with just 3 shots around but control point generation is not so smooth.
The New Lens
The New Field of View
