Quote Originally Posted by kapitman View Post
I don't have any experience or knowledge of this lens, but if you have the specs, you know they show it has large coverage, but is heavy and uses very large filters. All in all, I would go for the Nikkor.
The specs on the Fujinon CM-W series are available here.

The 450mm CM-W takes 86mm filters. Not really all that big for a lens this long. It's the same size filters as a 240mm APO Sironar-S and smaller than most 300mm and 360mm plasmats and most modern 8x10 wide angles.

It's well documented that the 450mm Nikkor M covers a LOT more than the published specs. I'm using one on 14x17 and have plenty of coverage. I don't have anything bigger to try it on, but the image circle needed for 12x20 isn't much bigger than for 14x17. I believe if you search the archives here and on the large format forum you'll find testimonials from several photographers who have successfully used the 450mm Nikkor M on 12x20.

Kerry Thalmann
Really Big Cameras