I am looking for a wide angle lens for my new camera and decided to try out the 12-24 I own.
From about 18mm you get no vignetting.
I read about adding a 1.4TC to your DX lens to avoid vignetting and decided to give it a try.
I own a Kenko pro 300 TC that works on all the lenses I own and carefully tried it out with my 12-24 on my D800E
I get a 17.3-34.6mm lens from the 12-24 with the TC. The advantage is I do not have to worry about spinning too wide and getting serious vignetting.
I have posted shots with and without the TC from 12-24mm (not every focal length in the middle) and am thinking for my vacation this week I can use what I have.
If you are curious what 12mm on the nikon 12-24 looks like on FF and want to see where the vignetting stops as well as what a 1.4TC does to the photos, here is the link to my Flickr account.
These were all shot JPEG large fine without any corrections in LR. I did pull them into LR to look and was surprised it did not show a 12-24 option but chose 14-24 for the lens profile. It also chose 14-24 on the photos with the TC attached. I have the most current version of LR4, so not sure why the Nikon 12-24 did not show as an option.
http://www.flickr.com/photos/36026557@N05/sets/72157632047710323/
EXIF is available on the photos