I always feel that I should buy a Canon lens for my Canon camera, and Sigma would just be a cheap knock-off. Is that the case?
My wife and I own three Sigma lenses: the "bigma" (50-500mm), my 17-70mm f/2.8-4, and her 30mm f/1.4 prime. We absolutely love them, for their respective strengths:
- Noone touches the Bigma for range. Yes, it's soft. Yes, it's unbelievably big and heavy. But it's a disturbingly versatile lens.
- The 30mm is incredibly sharp, and f/1.4 is something you just have to use to understand why you want it.
- My 17-70mm is a great compromise lens; it's almost always attached to my camera, and I switch off when I have a particular need.
And, quite frankly, it's tough to touch Sigma on price. As with all things, they have their good lenses and their bad lenses (just like Canon); be sure to check sites like photozone.de for quality tests before plunking down your money.
Sigma makes some great lenses, and Sigma makes some lenses that are of pretty poor quality. Canon is the same way... it's hard to make a brand-wide generalization.
A much better option is to do research based on specific lenses. I've found the lens reviews at FredMiranda.com to be pretty helpful.
I've had a lot of Sigma lenses in recent years and all have been pretty damn good.
- The 12-24 EX is a great lens and about as wide as you can go on full frame. I currently have the 10-20, which is nice and sharp and has the advantage that it can take filters whereas the 12-24 cannot.
- I have the 50mm f/2.8 macro mentioned above, this is a super sharp lens and a macro at a unique focal length.
- The 150mm macro is a legend and rightly so, a superb lens and I find also does well as a medium telephoto lens.
- I had a 70-300 sigma which was actually pretty good looking back. -I had but then sold a Sigma 70-200 f/2.8. This lens was too soft for me wide open, but it was significantly cheaper than the Nikon equivalent.
I'm sure none of sigma zooms match up to the 2.8 "pro" Nikon lenses, but then most are 1/3rd the size, weight and price, which is a Good Thing in my book.
Sigma lenses can offer excellent value, but it does depend which model you go for. I have a Canon 5D Mark II, which has a full-frame sensor, and I use two Sigma lenses with it: A 50mm EX-DG Macro and a 105mm EX-DG Macro; both of these produce excellent, sharp pictures. The only downside to these lenses is lack of USM focusing, but this isn't an issue in most cases, especially when doing macro work as I'd focus manually anyway.
Their 100-300mm f/4 is another lens I used which was also very good, though not quite so cheap.
On the other side, the 20-40mm zoom I bought from them was a dud, and didn't last long before being replaced with a Canon 16-35mm f/2.8 L II. Not cheap by any stretch of the imagination.
Conclusion: it appears to be hit and miss with Sigma lenses; there are some great ones, and also some that don't deserve a second look. Check fredmiranda.com for comprehensive reviews by users.
My experience is that some of the primes are on a par with their Canon equivalents - the 24mm f/1.8 and the 180mm macro are really good. The AF is always much slower. I find the colour cast different to the Canon L lenses - which are consistent with each other in my experience - but haven't found this to be a problem.
I have the Sigma 180mm macro (sorry, I can't find it on the US site) and the Sigma 120-400mm OS telephoto. I am very happy with these lenses and they were much cheaper than the brand lenses for my Nikon D50 and D60. A friend uses the Sigma 18-200mm on this D40 and I can't tell the difference from it and my Nikon 18-200mm (and I love this lens.)
DO NOT WASTE YOUR MONEY ON SIGMA PRODUCTS
I purchased a Sigma lens for my Canon EOS 7D and I can honestly say it was extremely poor quality. I used it three times in less than a month only for the focus ring to break on it and spew parts onto the floor. So less than a month old I sent it back to Sigma under warranty only for them to tell me I broke it and I would have to pay £75 to repair it. I told them to stick it and put the poor quality lens into the bin. I have thirteen Canon made lenses and not one of them has broke on me, my oldest lens is six years old now. So, from my experience you buy Sigma you get cheap and nasty quality with a useless warranty. My recommendation is always by your camera manufacturers lenses only. Be warned, spend a bit more and get quality, don't cut corners as it will cost you in the long run.