This was announced a couple of days ago, but I just came across it this weekend. Canon’s replacing their EF 15mm f/2.8 fisheye lens with a very wide fisheye zoom. The EF 8-15mm f/4 L fisheye zoom is the world’s first to offer perfect circular and full frame images.

Being in the market for a fisheye, this was pretty exciting news. It’s got constant aperture, and a zoom lock feature for different sensor sizes, limiting the focal length to prevent vignetting and preserve the best possible full frame view. Being a user of the Canon 5D Mark II (full frame sensor) and 7D (APS-C sensor), this is great as it makes the lens very interchangeable between Canon’s different sensor sizes, while still being able to achieve a full frame fisheye, as well as a circular fisheye on full frame sensor cameras:

Courtesy of Canon Digital Learning Center

Here are some additional sources on the new lens:

Target release date is January 2011, with a sticker price around $1400.