Sigma vs. Canon

December 28, 2010 10:05 AM

Sigma 18-125mm f/3.8-5.6 AF DC OS HSM vs. Canon EF-S 15-85mm f/3.5-5.6 IS USM, besides the obvious zoom range differences is the Canon really worth twice the Sigma? I've checked a number of reviews and it doesn't look like the Canon's advantage is as clear cut as the price would suggest.
posted by tommasz to technology (10 answers total)

I can't say that I have experience with any Sigma stuff, but usually when I hit a point like this I prefer to give my money to the company that has better ethics or makes ground-breaking technology, at least then the cash is going towards great science as well. And yes I even have that viewpoint when it's significant cash.
posted by zombieApoc at 10:17 AM on December 28, 2010

They're both consumer-grade zooms - the Canon may have a small edge in sharpness due to the fact it's not trying to do as much, and that it's IS tech is more mature than Sigma's. Not enough of an edge to justify such a steep pricetag, IMO.

A good source for lens reviews seems to be Photozone.de. They have write-ups on both lenses and sample pics.
posted by Slap*Happy at 10:27 AM on December 28, 2010 [1 favorite]

Sigma lenses have been hit or miss for me. I love my sigma 30mm 1.4, but had to return the first one I bought because it wasn't sharp. So if you go sigma make sure you test it and don't be afraid to return it for a second lense.
posted by meta87 at 10:29 AM on December 28, 2010

Not sure how helpful this will be, but I've more or less abandoned Canon-brand lenses for my 40d. I shoot semi-professionally (1 or 2 family portrait sessions a month, plus my own kids), and I haven't had the need to pay Canon prices. Personally I have tended to go with Tamron glass, and yes the focus speed is slower - at least compared to the one L-series lens that I have - especially in low light. However, if I can buy two lenses for the same price as one Canon lens, that makes up for it in my eyes.
posted by um_maverick at 11:02 AM on December 28, 2010

A quick google search yields this comparison.

The recommendation is to find the Canon 17-85 which I have used for many years. Very happy with it.
posted by cosmac at 11:07 AM on December 28, 2010 [1 favorite]

Here is a tool that will let you do a direct comparison between the two lenses. The Canon looks much sharper, but that is to be expected even based solely on their focal length range. The longer the focal length range, the lower the image quality.

Here are good reviews: Canon. Sigma.
posted by inertia at 11:21 AM on December 28, 2010 [1 favorite]

I have a sigma lens that I am quite fond of, along with a tamron and two canons. Never had any complaints about any of them. Of course, I'm pure amateur, so take my experience with a grain of salt.
posted by yeolcoatl at 1:41 PM on December 28, 2010

If you can part with the IS, Tamron's 28-75mm/2.8 is supposedly a fantastic lens.
posted by schmod at 2:14 PM on December 28, 2010

I think I'll just wait until the Canon's price comes down. I really want the better image quality. Thanks for the additional review sites to check in the future.
posted by tommasz at 10:52 AM on December 29, 2010

If image quality counts to your critical tastes, FWIW: I've never heard anyone anywhere brag about the glass in a Sigma camera. Canon, Nikon, Zeiss... these are the big-name optics houses, the Jaguar/Mercedes Benz/Porches of their market. Sigma is more of a Chevrolet: good products, but not really interested in making anything top-of-the-line. I wouldn't expect, therefore, their best optics to be better than Canon's mid-grade stuff, since they don't start with the ability to produce excellence.

FWIW.

(Frustrated optics engineer: why won't the buggers publish real optical performance data? Field spot diagrams, MTFs... Sigh.)
posted by IAmBroom at 3:47 PM on December 29, 2010