Introduction

Canon EF 28-135mm f/3.5-5.6 IS USM was first released in mid 1998 and was one of Canon's first lenses to incorporate an Image Stabilization technology. Priced at about US$450 (as of April 2007) the lens is clearly positioned for the entry level market with appeal to amateurs purchasing their first SLR or upgrading from a kit lens. The lens is designed to fit EF mount and on APS-C type cameras with 1.6x crop ratio, it would have a field of view resembling that of a 45-216mm lens on a full-frame body.

The optical construction of the lens consists of 16 elements in 12 groups including a single aspherical lens element designed to reduce various forms of lens aberration. As mentioned above, the lens includes a first generation image stabilization technology which helps gain an 2 f-stops when hand-holding the camera as well as a silent, ring-type USM AF mechanism. The lens also supports full-time manual focusing, has a minimum focusing distance of 50cm (1.6ft) and maximum magnification of 1:5 at 135mm. The filter size if 72mm.

Canon's consumer-oriented lenses typically do not sport high quality mechanics and Canon EF 28-135mm f/3.5-5.6 IS USM is not an exception here. The lens barrel is built from plastic and dual cams, which extend during zooming, wobble inside the barrel. The zooming ring is rubberized but the focusing ring is not and feels a bit sticky. The lens is relatively compact (when the cams are fully collapsed), measuring 79x97mm (3.1x3.8in) and weighing 540g (18.9oz). The filter size is 72mm and the lens can accept circular polarizers which can be attached to the front thread.

 

Image

 

The factory box includes the Canon EF 28-135mm f/3.5-5.6 IS USM lens, front and rear lens caps, manual and warranty cards. The lens accepts gelatin holder adapters as well as EW-78BII lens hood. You can also use Canon's extension tubes EF 12 II and EF 25 II with this lens.

 

Summary
Lens Composition 16 elements in 12 groups
Angular Field 75-18 degrees
Minimum Focus 50cm/1.6ft
Focusing Action AF/MF, USM
f-stop Scale f/4-f/22, camera-controlled
Filter Size 72mm
Lens Hood EW-78BII (optional)
Weight 540g/18.9oz
Dimensions 78.4x96.8mm/3.1x3.8"
Lens Case LP1116 (optional)

 

Field Tests

Canon EF 28-135mm f/3.5-5.6 IS USM achieved best results in the 28-50mm range. Here both center and border quality remained reasonably sharp. From 50mm an up the lens shows noticeable softness around borders throughout the aperture range. The fact that the lens is quite slow at its telephoto zoom range does not really help here either, so overall I found myself often avoiding the telephoto side. AF performance was quite good throughout the zoom range and the lens did not hunt much even in low light conditions.

The lens showed practically no visible barrel distortion throughout the zoom range. At 28mm the lens showed minor vignetting which could be controlled by stopping down to f/5.6 or f/8. At 50mm and beyond, vignetting is pretty much minimal, so there's nothing to worry about. Chromatic aberration also seemed well under control - CA was very minimal in the center and slightly more pronounced in the corners, but again nothing extreme. The 5x zoom of this lens was quite useful in some situations, however keep in mind that on  APS-C cameras the lens looses its wide aspect, so the overall zoom range is probably going to be less exciting.


Lab Tests

Please note that MTF50 results for APS-C and Full-Frame cameras are not cross-comparable despite the same normalized [0:1] range used to report results for both types of cameras.

 

Canon APS-C: The lens showed very mixed results in the lab. Performance in the center was quite decent from 28mm all the way to 50mm, but quickly degraded towards the telephoto range of the zoom and at 135mm was just plain average. Performance at the borders was even worse - at 28mm, the lens was moderately sharp, but quality started to fall off pretty quickly starting at 35mm. The lens performed consistently at different aperture settings, which in general is a positive characteristic. Overall, you would achieve best results at 28mm where you will be able to get very good 11in prints and OK 16in prints. At the telephoto side, border quality is quite soft, so don't expect any miracles here. Conclusion? The lens is certainly not suitable for telephoto photography, but might be OK to use in the wider zoom range. But even there the lens does not really deliver any punch and comes short in overall quality. Lens for amateurs and general masses - maybe, lens for advanced and professionals - unlikely.

 

MTF50 (Line Width/Inch on the Print) @ 28mm
MTF50 (Line Width/Inch on the Print) @ 28mm

 

MTF50 (Line Width/Inch on the Print) @ 35mm
MTF50 (Line Width/Inch on the Print) @ 35mm

 

MTF50 (Line Width/Inch on the Print) @ 50mm
MTF50 (Line Width/Inch on the Print) @ 50mm

 

MTF50 (Line Width/Inch on the Print) @ 70mm
MTF50 (Line Width/Inch on the Print) @ 70mm

 

MTF50 (Line Width/Inch on the Print) @ 100mm
MTF50 (Line Width/Inch on the Print) @ 100mm

 

MTF50 (Line Width/Inch on the Print) @ 135mm
MTF50 (Line Width/Inch on the Print) @ 135mm

 

Chromatic aberration was quite modest with Canon EF 28-135mm f/3.5-5.6 IS USM - at 28mm CA was less then 1 pixel in the center and slightly more around the borders. Once stopped down to f/8, CA becomes pretty minimal and certainly is nothing to be concerned with. Vignetting is slightly more pronounced at 28mm and nonexistent at 50mm and beyond, but keep in mind that on cameras with full-frame sensors vignetting is very likely going to be higher.

 

Image borders @ 28mm (100% crop): f/3.5 vs f/8
Image borders @ 28mm (100% crop): f/3.5 vs f/8

 

Canon FF: Coming soon...

 

Alternatives

Canon alone manufactures over half a dozen standard zoom lenses. Add to that zooms manufactured by Sigma, Tamron and Tokina, and suddenly choosing a good lens becomes an exercise of futility. Start your search with Canon EF 24-105mm f/4L IS USM (review) or Canon EF-24-70mm f/2.8L USM, both of which offers excellent image and build quality at almost twice the price of Canon EF 28-135mm f/3.5-5.6 IS USM lens. If you're using an APS-C camera, consider Canon EF-S 17-55mm f/2.8 IS USM (review) which is probably the best EF-S lens available on the market. If you prefer to stay within US$500 budget, you might want to take a look at Sigma 18-50mm f/2.8 EX DC which packaged a very decent image performance at an attractive price (but keep in mind that this lens has a reduced imaging circle and therefore is suitable for APS-C sensor cameras only). Finally, consider Tokina AT-X PRO DX AF 50-135mm f/2.8, which is also an APS-C lens which delivers exceptional performance at very decent price.

 

Recommendation

Canon EF 28-135mm f/3.5-5.6mm IS USM offers an average image quality at an average price, which makes the lens... well... average. At the wide side of the zoom range, the lens offers an OK overall performance, but the quality degrades drastically towards the telephoto range. Combine this with an average build quality and relatively slow speed at the telephoto side of the zoom. The only positive thing going for this lens is the Image Stabilizer, which is hardly enough to turn the entire package into an attractive offer.