When I first bought my Canon 500mm f/4 telephoto lens in late 2006, I took it to the Nashville zoo to test its sharpness. I also tested the sharpness of my new (at the time) 1.4x and 2x teleconverters. You can see why I was impressed. This white tiger is tack sharp -- even the whiskers. I took this shot with the 500mm plus the 2x converter giving me 1000mm of focal length. I used a tripod with a gimbal head, and my settings were 1/125, f/8, and 640 ISO. Today, with the ability to use faster shutter speeds and higher ISO numbers, I would have used at least 1/1000 even though I was on a tripod. Since 2006, Canon’s 500mm has been improved as has the 2x teleconverter, but even so, you can see why I feel confident in using so much glass to get distant shots. If the camera and lens aren’t stabilized by a solid tripod, a fast shutter is essential in guaranteeing sharp pictures. All white tiger shots are done in captivity because there are no known white Bengal tigers in the wild.