The Zoom Lenses
Canon EF 28-90mm f/4-5.6 (USM) – Price class $100
This is Canon’s low end basic zoom lens, often sold in “kits” with an EOS body. It’s small, it’s light and it’s cheap. The construction uses lightweight plastic, even for the lens mount – though the optics are all glass. The lens feels fairly flimsy and I don’t think I’d want to try drop testing it!. Though it has manual focus, it has no manual focus ring. To focus manually you rotate the front end of the lens barrel. Focusing is loose and undamped and quite sensitive to small rotations of the barrel. In addition the barrel wobbles up and down quite a bit, which isn’t a good sign for optical alignment! There is no distance scale (hence no IR focus markings). A basic lens at a low price. Though the lens is available in USM and MM (Micro Motor) versions, this isn’t the ring USM motor with FTM (full time manual focus). There really isn’t a significant difference between the MM version and the USM version, though Canon claim the USM version is quieter and focuses faster. It probably is and does, though I’m sure the difference isn’t very significant.
EF 28-105mm f/3.5-4.5 USM – Price class $200
This Canon zoom lens is a huge step up. It’s solidly constructed with a metal lens mount. It has a ring USM motor with full time manual focus, a distance scale and IR focusing marks. It’s a little bigger, a little heavier and about twice as expensive as the 28-90, but it’s a much better constructed lens. Manual focus is smooth, well damped and geared so that fine adjustments can be made, as you would expect from a ring motor FTM USM based lens. The current version is the “II” model, though it is optically identical to the original model which was tested here. The differences are mainly cosmetic.
EF 28-135mm f/3.5-5.6 IS USM – Price class $400
This Canon zoom lens is significantly larger and heavier than the 28-105 but is of a similar solid construction with a metal lens mount, ring USM motor, FTM, distance scale and IR focusing marks. It also has image stabilization which allows it to be hand held at shutter speeds about two stops slower than would otherwise be possible and still get sharp images. It costs about twice as much as the 28-105. It takes a significantly larger filter than the other two lenses (67mm vs. 58mm). Manual focus is smooth, well damped and geared so that fine adjustments can be made, as you would expect from a ring motor FTM USM based lens. This lens uses one aspheric element (neither of the other lenses tested have aspheric elements) which may contribute to better performance – at least that’s the idea behind using aspheric elements




































