There’s a lot packed into this compact lens, starting with a generous 4.8x zoom range that covers the entire gamut of frequently-used focal lengths for full-frame photography.
Canon EF 28-135mm f/3.5-5.6 IS Macro USM Review
The AF mechanism is internal and employs an efficient Ultra Sonic Motor (USM) that leaves the focusing ring undisturbed in automatic mode but with the option of full-time manual focusing intervention if this is required. Although the manual focusing ring is very narrow it falls naturally to hand and is therefore easy to use despite its small size.
The zoom ring feels smooth in normal use but becomes jerky when moved slowly. This can be significant when attempting close-up photography because the greatest magnification appears to be achieved using focal lengths of around 100-130mm rather than the 135mm maximum setting. Although the lens can magnify only to 0.19x it bears one of Canon‘s cheeky macro labels: if true macro photography is required then the optional EF25 Extension Tube needs to be fitted.
Optical performance, in terms of MTF testing, is excellent. The resolution figures are all comfortably above 0.25 cycles-per-pixel from wide-open down to f/16 and at f/8 the figures peak well above 0.3 cycles-per-pixel. Some chromatic aberration was seen at both ends of the zoom range during technical testing, but this should not be so severe as to mar real-life images.
Image stabilisation is said by Canon to aid photography in low-light conditions without the need for either flash or a tripod but the greater benefit is reduced camera shake through the viewfinder under all lighting conditions. It is also useful when deliberately setting a slow shutter speed to record blurred subject movement without blurring the entire image. A good example of this situation is when trying to blur an aircraft’s propeller without blurring the aircraft itself.
Leaving aside its macro label, the only other issue is the fact that its restricted maximum aperture, especially at longer focal lengths, will impose some creative limitations on picture-taking. Overall, however, this is an impressive and competitively-priced lens.
This is an impressive set of MTF results that shows lens resolution holding firm from wide-open to f/16.