Cheap canon product.

My all time favorite lens (2008-07-25)
I am pretty much a full time user of this lens with my type of photography.

I've taken this lens on many skydives (I am a freefall photographer) and it has even survived a crash, without a single scratch on it.
I have used it in AF in freefall, but I prefer to shoot MF and use the depth of field this lens provides.

5 years and 2000 jumps later this lens is still my favorite and produces amazing photos time after time. Even shooting into the sun, or having the sun in the photos, it produces a very nice flare (a signature effect in a lot of my photos)

I have to say the build of this lens is truly amazing and the image quality continues to amaze me... At the time this lens was a LOT cheaper than the Canon option, and I have not regretted my decision to go with this lens instead of the Canon.

Top of the line lens!

Good lens but a good tip before you buy (2006-01-13)
If you are shooting with a compact chip camera like the 20D or rebel xt, you will be happier with the 8mm fisheye. This 15mm fisheye will just be a really distorted wide angle lens due to the 1.6 factor. If you love the fish eye style and have that camera, you'll need something WIDER to compensate for your smaller chip.

I was disapointed with this lens for that reason. The Sigma 8mm is great. A note to the reviewer below. Sigma makes some good lenses and bad ones. This is a good one and you probably got a bad copy. It happens often enough with sigma gear. With this lens, its good to go and try one at your local camera shop and make sure it has the style you want. Bring YOUR camera with a chip in it and take a few shots and go home to check them out. Decide if you like the style and if that piece of glass is a good copy.

I got a good copy and was still disapointed because of my lack of knowledge. Sounds like you got a bad one.

Big bang for the buck (2004-12-02)
15 years of photography experience here... The Sigma 15mm fisheye has been extensively reviewed and compared by other websites (go ahead and search) and this is a very good product. The canon has a tighter focus and a *touch* faster in focusing, but with the massive depth of field with this lens, it's not a problem at all.

Be aware that if you use this on a 1.6 crop factor digital SLR that has APS sensors like my 20D or digital rebel, then the fisheye effect is not as pronounced on film or 1.3 or full frame digital SLRs.

Watch lens flare should direct sunlight hit it also...but that happens to any lens that has protruding or bulbous lenses.

This is a much better bang for the buck lens than the canon equivalent which costs significantly more. If you search around, you can find much lower prices on this lens.

Worst Experience Ever (2004-05-27)
I wanted to use this lens with my Canon EOS-10D and I was shocked with its performance. The AF only works for objects closer than 4 feet and it does not focus on objects farther than that. First, Sigma told me that the serial number I bought was old and the lens needed updating for it to work with Canon digital SLR Cameras. I have no idea why they distribute outdated lenses to their resellers.. That's not all, I tried manual focus, and the photos came out very soft even at very small apertures (large f-stop number)

After 4 weeks I get the lens back from Sigma in the same condition. I can only call this horrible service and a very bad product.

My recommendation is pay a little extra and either go for the Canon EF 15mm f/2.8 fisheye or the Canon EF 17-40mm f/4 (which I did).

wahoo!!... (2001-12-08)
i am a fisheye lens addict. i have had this lens for a few months now, and i use it for almost everything. the lens was worth every bit i payed for it. and the sigma customer service was so fast and easy. the lens takes clear sharp pictures everytime. this lens takes the best skateboarding and band pictures! if you are considering this lens, i would definately reccomend it. i love how the pictures can either be circular or full frame. its a great investment.......