Nikon 10.5mm Fisheye modification for FX (Full frame sensor)


A little history: The Nikon 10.5mm DX fisheye provides about a 140 horizontal degree angle of view on an APS-C sensor (1.5 crop factor). On an FX (full frame) body if you use it in full frame mode you can see the protective fins ( built in lens hood) that come off the top and sides of the front of the lens which are used to protect the lens and to hold the lens cap on. Here is an example photo:

Before:



Obviously this isn't really the look you want from a fisheye so I set out to modify the lens in order to produce wider images.

First: I needed a small fine tooth (20-30TPI) hack saw that I picked up at Canadian Tire for $15.
I then marked off where I wanted to cut the lens with electrical tape in order to keep a straight cut all the way around:

Then I cut all the way around in even increments so that the whole thing came off at the same time.

Cutting:



When you get close to being through the plastic if you've got a good feel you can tell that you've cut through it just like cutting negative mark up plates for presses.

Taking off the fins:




The lens after:
For anyone attempting this (and I take NO responsibility) cut closer to the lens element so that the dust protection is still covered up. Note that you can see a gap from the top of the cut to the bottom of the lens element.




Photos after:
A perfect fit! (In FX 8x10 format)
Compare the above "Before" image to the after ones.
The angle of view is now wider than an 8mm sigma on an APS-C camera.

What's gained:
Here, the extra area provided by cutting off the fins is illustrated with the red outline for comparison. Everything outside the red line is what is gained by cutting off the lens hood.