I purchased the Canon 10-22mm lens a few weeks ago, and I just brought it out on a shoot yesterday. I mostly use my t3i for video, but I ran into an issue that I haven't been able to figure out. When I started using my 10-22mm lens to get wide angle shots, I found that I couldn't adjust the aperture with it. I checked all of the settings, with Movie Exposure set to Manual, and nothing seems to work. I press the AV button and turn the dial -- and nothing. I closed it down to 25 and it was still letting in as much light as it did at 5.6. The only button on the lens is a switch for manual/auto focus. If I change to a different lens (I have 3 other lenses: 50mm, 18-55mm, and 55-250mm), all let me manually control the aperture, without changing any of the settings.

I ended up just letting it do its thing while shooting indoors, but where I really ran into trouble was filming outside. I set my ISO to 100 and everything was completely blown out. The only way I could use the lens outside was if I changed the Movie Exposure setting in the camera to Auto. But then I have no control over the ISO, shutter, etc. And to make things even weirder, if I switch over to the M mode on the t3i to take pictures, I have full manual control over everything -- including the aperture. It just doesn't seem to work in Movie Mode. Has anyone ran into this issue before? Did I buy a broken lens, or is this lens only supposed to work for pictures and not video? Since I don't take a lot of pictures with this camera, I feel like I just threw away $600 for a useless lens. Surely there has to be something I'm missing.