Summary: Canon EF 70-200mm f/4L IS USM is clearly one of the best EF mount telephoto zoom lenses available on the market. The lens shows outstanding image quality with particular strength in the 70-135mm range. Combine this with excellent build quality, well controlled artifacts such as vignetting and chromatic aberration, and you get a winner on your hands.
Excerpt: Gary Wolstenholme takes a look at how this compact telephoto zoom lens performs. Canon's EF 70-200mm f/4L IS USM costs around £800 and has an Image Stabiliser, silent Ultrasonic focusing with full time manual override and is sealed against dust and moisture.
Pros: Excellent optical quality, Superb build quality, Very effective image stabilisation, Fast to focus, Sealed against weather and dust, Light weight
Cons: Sometime miss-focuses near minimum focus distance
Conclusion: The EF50/1.2L is a totally new optical design (there was an old FD 50/1.2L) and uses a molded aspheric rear element (the 50/1.0L used two very expensive ground and polished aspherics). It has a true ring type USM motor and a high speed CPU for fast focus. It has an 8 element, 6 group construction and an 8 blade aperture. Minimum focus distance is 0.45m and the filter size is 72mm. The lens measures 85.4mm in diameter, 65.5mm in length and weighs 545g.
Excerpt: Take one of Canon's most popular lenses, the Canon 70-200mm f/4 L , add an up-to-4-stop Image Stabilizer and you get the Canon EF 70-200mm f/4L IS USM Lens. If you don't need the subject-action-stopping and background-blurring capabilities of the faster Canon EF 70-200 f/2.8L IS Lens , this lens will deliver everything else you need in a smaller, lighter and less-expensive package.
Canon EF 70-200mm f/4 USM L IS (full format) - Review / Test Report
23 January 2009
Conclusion: The Canon EF 70-200mm f/4 USM L IS is an amazing lens. It is truly outstanding when used on APS-C DSLRs and it suffers only from a minor quality deteriorations on full format DSLRs. The resolution figures are easily on prime levels throughout the whole range and even at max. aperture. Unlike most other full format lenses it manages to keep the vignetting on a moderate level. Lateral CAs and distortions are usually also nothing to worry about.