Let me first start off by saying - long time canon user. I own 6 or 7 lenses, including three L series lenses, and this is by far one of my favorites - if not my absolute favorite.

I shoot mostly glamour and erotica type work on a 20D. So right there, this lens is not a true 15mm for me - but 1.6x15mm.

It's sharp as a tack. It's light weight. It's very short (I call it the nub lens). And it's autofocus is amazing.

Very little barrel distortion...

and highly recommended. This lens is probably as sharp (if not sharper) than my 24-70 2.8L or my 17-40 4.0L lens.

The fisheye lens is a lot of fun, and I enjoy using mine. However, I find that the practicality of the lens is minimal. I don't usually want my "serious" photographs to have fisheye distortion.

I don't tend to like the 1.6x crop on Canon's lower-end digital SLR cameras, but with the fisheye this has an interesting benefit: it's reasonably easy to use the fisheye as a standard wide-angle lens, since most of the distortion is removed by the 1.6x crop. You can still get distortion, but it's a lot easier to compose a shot without it using a 1.6x camera than a full-frame camera.

Either way, lots of fun. Buy one for the enjoyment, or even for professional assignments if your work calls for it, but think about if you really want the distortion before getting one of these.

For anyone who wants to make their photos different, this is the lens! With 180 degree capacity and fabulous auto focus capability, this lens takes an ordinary photo and turns it into something extraoridinary. I shoot for magazines and many of the photos that are selected for publication are taken with the lens. It's an expensive toy, but worth the money when you see the results. I highly recommend it.

I bought this lens as I was walking out to Africa for a month and a half safari. I didn't own a true wide angle lens and I had just spent most of my budget on a 70-200mm USM "L" lens and a 1.4x extension.

I wanted to get the widest lens I could get but I didn't have the big bucks to get the 16-35L or the 14mm L so I got this lens figuring I could correct in Photoshop CS2 later.

This is what I found:
1) I have a 20D and it doesn't barrel distort anywhere near as bad as I had thought it would....I imagine it distorts quite a bit more on a 5D or other full frame sensor but on the 20D, 10D, 30D, or Rebel it is not that bad.

2) It does distort enough even on the 20D that its noticable on every single inside shot and on many panoramic shots....to the experienced professional, you'd notice it even in panoramas.

3) For the computer person: I find it very easy to correct the barrel distortion in Photoshop CS2 very easily....I use a plugin (there are several on the web)

4) I tend to like the barrel distortion look on some of my pictures.


Pros
1) Image Quality is superb. For not being an L lens, this lens has some amazing color, sharpness, and saturation. They spared very little in grinding this lens. Some of my best African pictures, daytime and nightime were taken with this lens and they were fabulous.

2) Build pretty well, metal mount, metal integrated hood...but not up to L standards by any means....to its credit, it survived 14 days by vibration ridden truck treking across the Kalahari desert with all its dust, mokoro canoeing in the okavango delta for over a week, hiking, elephant riding, and the five diamond resort at victoria falls (the last one was easy for the fisheye)...

3) It is a Fisheye lens and if used properly, it can create some amazing pictures and views...for example In Botswana in the Okavango, I knelt down next to a Gigantic Baobab tree and pointed it up towards the sky, The fisheye captured not only Rex the guide standing next to the tree but the entire massive trunk of the Baobab AND ALL of the canopy of the tree way above. Everything! I know of few lenses that would let me do that. It was an amazing shot only possible with a Fisheye.

4) It focuses to about 12inches.

5) f/2.8 makes it very good in low light situation.

6) The integrated hood comes complete with a nice metal cover.

Cons
1) Its not built like an L:
a) no USM motor so you can hear the whir as it tries to focus
b) no moisture seals etc
c) It does have a metal mount

2) It is a fisheye lens -- I found out after a month and a half what this meant....it doesn't stay on my camera much. I take it out when I need a certain effect or when I plan to retouch in Photoshop. It distorts visibly on a 20D and I imagine quite a bit more on a full frame.

3) Integrated Hood...can't put screw on filters...but it does have a gel filter holder.

4) No bag.

My veredict:
1) I've purchased a 16-35mm Canon "L" and that lens stays in camera most of the time when I want wide-angle but when I need a special look or I really want to capture everything, I bring out my 15mm Fisheye. I won't sell it, I don't regret buying it. I learned what a specialty Fisheye lens is and its staying in my arsenal for those special shots.

2) I can't compare against non-canon lenses but I can say that Canon quality here is extraordinary. I would knock them on the construction but the lens is built well enough and the "glass" itself is spectacular so 5 stars.

3) I ordered from Amazon 3 days before my trip --- it arrived the next day. Great Service. Thx Amazon.

Just as the title states. Canon makes the best lenses on the market. The 15mm fisheye is very sharp. It is my primary lens for shooting surfing in the water. For the price, you can't go wrong.

When used on a camera with a crop factor , the 15mm lens isn't as extreme as it seems. For example, on my EOS 20D the "35mm equivalent" is 15mm * 1.6 = 25mm. I do plan on getting a full-frame body in the next few months, and plan to enjoy the lens even in its full super-wide-angle glory.

This lens does have barrel distortion inherent in all fisheye designs BUT these can be enhanced, diminished or completely removed by commonly-available plugins. (I use ptlens, dxo, and to a lesser extent, the ones built into Photoshop CS2 and CS3.) Here's the important part: if you're willing to deal with barrel distortion in post-processing (and you should be), the 15mm is the best super-wide lens available. It's lighter, much cheaper, and, to my eyes, equal in image quality to the 14/f2.8L.

Bottom line: Excellent lens, excellent value. The total cost of the lens plus post-processing software is much less than the more expensive rectalinear 14mm lens. This lens is one of my favorite possessions. You will not regret owning it!

This is an amazing Fisheye, a must have lens for items that are too large to be captured by regular lenses.

DIDN'T REALLY KNOW WHAT I WAS GETTIN INTO WHEN I BOUGHT THE LENS BUT I'M SUPER HAPPY WITH IT. IT HAS A HUGE ANGLE OF VEIW AND WITH A LITTLE HELP FROM PHOTO EDITORS U CAN MAKE SUPER LONG PANARAMIC PHOTO'S. THING TO BE CAREFULL ARE GETTIN ARMS AND FINGERS ETC. IN THE PHOTO'S. IT'S EASY TO FORGET ABOUT THE WIDE ANGLE OF VEIW. THERE IS DISTORTION OF COURSE WITH ANY FISH EYE BUT IF A FISH EYE IS WHAT UR LOOKING FOR THEN THIS IS THE LENS FOR YOU. WITH A AFFORDABLE PRICE.

I have been a fisheye fan for years. Photos taken with this type of lens can be very striking because they enable a viewer to see all at once a scene that cannot be viewed as a whole normally. A fisheye or other superwide lens is often the best way to capture a big landscape. No other lens has better depth of field making it possible to take photos in sharp focus from a few inches to infinity. Barrel distortion is largely eliminated or disguised in a landscape photo by putting the horizon in the center of the shot.

My only quibble with this lens is that the corners can break down on a full frame camera such as a 1Ds or a 5D. At f4.0 and above focus in the corner is noticeably soft and there is considerable chromatic fringing. It is only in the extreme corner so cropping that out or shooting at a higher aperature solves the problem.

This has been an Amazingly fun lens. Although the quality is not an "L" series canon, the very minor lack in sharpness and contrast, is made up by the awesome "fisheye" images produced by this lens. Talk about seeing things differently, this lens will will do that and some.

Enjoy using this canon wide fishy eye lens. Not so fishy when I first used it on my canon 40d but learned to love it. I take it everywhere. It's kinda loud but if its to loud your to old to use it.

Fantastic!
I have often wondered why they don't bring out a newer version of this lens as this is fairly old now and what with the specifics of the digital camera I was expecting to have to be careful how I used this lens (especially as I am using the 5D). In actual fact the quality is amazing. No picture fall off like you can get on the zooms with the large sensor (such as 24-105 for example). I must however add that this is just based on my first impressions and first experiments with the lens but my feeling is that it won't let me down.

I really like the sparkly, crystal-clear images this lens produces. I was after the lens distortion, and was pleased to see the other benefits of using the lens as well. It's quite a versatile lens.

That it will not take a filter and the lens glass bulges outward is a little scary from a lens-protection standpoint. I would not recommend this lens to anyone with sloppy handling techniques, and I CERTAINLY would never loan it to ANYone, too much danger of damaging the glass.

It's pricey. That it's not a 'great deal' is the only reason I gave it 4 stars rather than 5.

I have used this lens at Division 1A football games this season. I use it on a 5D to take shots of the stadium. It is tack sharp. Last night I saw a six foot wide (!) canvas print the university had made I shot with this lens; even with close inspection it held up nicely. If you must have a sharp lens this is the one.