Rocky Mountain National Park with the Sigma 10-20mm f/4-5.6

The Sigma 10-20mm lens is a reasonably well built lens compared to it’s Canon counterpart. The Canon just felt very cheap, the body was plastic, tolerances weren’t great and it felt lightweight. The Tokina, by comparison, is built like a tank so it fit well into my build quality standard. It’s bigger, well constructed and has great optics. The Sigma is in between the Tokina and the Canon in terms of construction. It’s lighter but doesn’t leave one with the sense that it’s built poorly that the Canon 10-22mm did.

For optical performance the Tokina was superior to both lenses. The f/2.8 aperture didn’t hurt either. There seemed to be more barrel distortion on the Tokina and the zoom is limited but I didn’t find that to be a big detraction since ultra-wide angle lenses make objects look pretty small anyway. The Canon and Sigma do have more zoom which is a nice but not critical feature for me.

Where I have a problem with the Sigma is with lens flare when shooting the sun. Whenever I’m shooting sunrises and sunsets, there isn’t a nice clean star burst like I’m used to with better lenses, such as the Canon EF 17-40mm f/4L. It has a unique splitting effect at the ends of the starburst that is unattractive. Further, and more importantly, the flare isn’t a nice, tight and manageable effect, it blows out the entire frame. A technique that I learned where you use your finger to block the sun in one frame then shoot another with the sun fails to resolve this issue. It’s just ugly. Note that when I get this effect I’m shooting f/16-f/22 with a polarizing filter and graduated neutral density filters.

I have not tried the Tokina in these conditions for comparison.

Sunset on Long's Peak

The last comparison is price. The Sigma is the least expensive of the three UWA lenses I tried. I ultimately made the purchase based on price and the fact that I could easily get back 80% of it on craigslist.org if it just wouldn’t work. It doesn’t seem like a risky gamble at all. And I do get some reasonably nice pictures from it. The Canon didn’t present me with a compelling reason for it’s higher price (the Canon brand isn’t important to me for this type of lens).

Regardless, if you avoid the situations where the Sigma fails, it’s price point makes it a good choice for APC-S sensor Canon cameras.