Sunrise above a fog bank covering Boulder, CO

I got up early on Monday morning thinking that there might be an inversion happening since it occurred on Sunday as well. An inversion is when a layer of air pushing another down on the ground. Historically, in the Denver Basin, this has meant poor air quality. And while that may have been the case, the scene above the clouds is completely different.

I’ve been hoping that I get to see this weather event and even more so to photograph it. I think it’s a particularly unique and beautiful situation and some of my favorite photographs have been of this.

The back-range the day before the sunrise image

Having had the intuition that the fog in Boulder might have been part of an inversion, I got up early and headed out with extra strong coffee in hand. I decided that since I may be wrong about the inversion that somewhere close by would be best so I chose to drive up to Sugarloaf Mountain. You can hike to the top and there are some pretty spectacular views of the whole Front Range as well as The Plains.

I knew I had made the right decision when, after driving for 20 minutes in fog, I broke through the clouds and saw stars in a clear sky. That was a good moment.

I parked, put on my pack and hustled up to the summit. I sat down for a few to minutes to catch my breath and contemplate the beauty of what I was seeing. The fog below was actually receding, the wind was blowing and it looked like a roiling sea of clouds, always in motion. Although there were some large, yellow glowing areas where the local towns were, the clouds blocked a lot of light pollution so the sky and all it’s stars were clear and bright. These are the moments that keep me walking into the mountains year after year. They are a profound gift which is also why I like to share them.

Indian Peaks Wilderness Area

After a while, I stumbled around in the dark to find some reasonable compositions then setup my camera and started shooting. I moved around to play with the burned, dead trees and some other foreground subjects. I even shot some images of the back range too (I’ll have to head back up now that I have a feel for the location). But the call to parenting duty got stronger so I packed it in at 8 a.m. and headed back to town.

What a great morning!

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.