Image Stabilization Test: Canon 70-200mm f/4L IS

Canon has been a leader in image stabilization technology since they essentially invented it for photograpic application a number of years ago. (Introduced in 1995, the Canon EF 75-300mm f/4-5.6 IS USM was the world's first interchangeable 35mm SLR lens with image stabilization built in.) One of the latest expressions of Canon's IS technology can be found in their excellent EF 70-200mm f/4L IS USM lens. The popularity of this lens and the solid IS performance it delivers led us to choose it for the first public unveiling of our IS testing.

Top-Level Summary

The IS system on the Canon EF 70-200mm f/4L IS performs beautifully, and the degree of stabilization it provides is very evident when framing your shots through the viewfinder. Our two test shooters highly praised its feel and handling, and appreciated the confidence it gave them that they were capturing sharp shots. Overall, it's safe to say it's one of their favorite IS lenses to date, out of probably 25 or so we've had through the lab over the last two years.

Canon claims "up to 4 stops" of image stabilization performance for this lens, and while it's possible that some photographer might see that much benefit, in our tests we found anywhere from a bit under two to a bit under three stops of improvement.

As we're finding often to be the case, we saw less improvement at the wider angle end of its zoom range, and our steady shooter saw less improvement than our shaky one. (We'll call them Steady and Shaky for short from here on out.) Perhaps thanks in part to the mass of its metal lens barrel and optics, Steady could hand-hold this lens (attached to a Canon 20D body) down to surprisingly low shutter speeds, even with the IS turned off. At 70mm, Steady managed sharp shots down to only 1/40 second, well below the 1/FL rule of thumb speed of 1/112 second. With IS on, his average shots were sharp down to an amazing 1/11 second, an improvement of 1.9 stops.

By contrast, Mr. Shaky was performing much closer to the 1/FL guideline with this lens/camera combination, shooting at 70mm with acceptable average sharpness down to 1/112 second with IS off, and down to 1/24 second with IS on, for an improvement of 2.3 stops.

At 200mm, the IS helped more. Shooting with IS off, Steady captured acceptable sharp shots down to 1/120 second, again significantly surpassing the 1/320 second 1/FL guideline for that focal length on the 20D body. With IS on, he could shoot down to 1/25 second (at 200mm actual, 320mm effective!), for an improvement of 2.3 stops.

At 200mm, Shaky could hand-hold with IS off down to 1/346 second, again close to the 1/320 second 1/FL guideline. With IS on, though, his average limit improved to 1/49 second, an improvement of 2.8 stops.These tables will probably be all that 90 percent of our readers want to know about our IS test results: They give a good idea of what to expect from a system, based on how steadily you can hold a camera. We do have many readers who want to know more of the technical details, though, so we've prepared more in-depth graphs for them. If you're part of the 90 percent, you can stop reading here and go back to the IS review you were just reading. For the remaining 10 percent, read on below.

Overall, the Canon EF 70-200mm f/4L IS delivered excellent IS performance, with improvements in slowest usable shutter speeds ranging from rougly two to three stops.

Performance Graphs

For those wanting a little more detail on how the EF 70-200mm f/4L IS performed, here are the performance graphs showing our actual test data. (See our article How to Read Image Stabilization Test Results for an explanation of these graphs. Techno-fanatics interested in the gory details of our test methodology should read our Image Stabilization White Paper.)