For Cropped Sensor Shooters
The Canon 8-15mm fisheye is one of the most exciting lenses to be released in a long time. It has some very cool features for both full-frame and cropped shooters, but there does seem to be some confusion about who this lens is best suited for. At a retail price of $1499, the Canon 8-15 fisheye lens is not going to be for everyone. It is often compared to the Tokina 10-17mm, and on a cropped sensor camera the Tokina is probably the closest thing to it but at less than half the price.
If you are only shooting on a cropped sensor body it is a very tough decision. The Canon is a better built lens. You will get slightly sharper and contrast-y images straight out of the camera and the most noticeable improvement will be less chromatic apparition. This is a big deal for me, but with a little time spent in post-production most users will not see a huge difference, especially if you don’t spend a lot of time viewing your images at 100%.
The useable zoom range on a cropped body is 10-15, so you lose that little bit of extra reach that you would get on the 17mm end of the Tokina. You can of course shoot at 9mm and 8mm but you will start to see the curved corners of the lens. If you want the absolute best image quality then the Canon lens is for you, but if you are a crop only shooter, the Tokina’s versatility, low cost and excellent image quality probably will make it a better overall choice.
Canon 8-15mm fisheye – For Full-Frame Shooters
For those shooting full-frame there is not much to compare the Canon 8-15mm to. Canon did make a 15mm fisheye (it has been recently discontinued), but the 15mm end on the 8-15 is not only sharper, but it also focuses to just millimeters in front of the glass. The older 15mm fisheye required too much working distance for really good close focus wide-angle work. Sigma makes a 15mm fisheye that focuses pretty closely, which I have heard good things about but not personally used.
At the Canon 8mm end of the lens you get a full circular fisheye. I happen to really like the look of circular fisheyes, but not so much that I would have invested in a lens like the Sigma 8mm or to have spent a whole dive committed to that shot. Now I don’t have to worry about that anymore. I have the best 15mm lens on the market, and when I want a special effect full circular shot I just zoom into the 8mm end. Full-frame shooters are not really going to use the zoom range between the 8 or 15 ends. Of course you can shoot at any zoom range but you will get partially round corners that are not very useful.