Introduction

Canon EF 135mm f/2.0L USM is one of the fastest telephoto lenses currently being manufactured for the EF mount. Priced at about US$900 (as of June 2007), the lens is not necessarily going to be the first choice for mainstream consumers, but it remains affordable for serious amateurs/prosumers and (obviously) professionals.

The optical construction of the lens consists of 10 elements in 8 groups including 2 UD (ultra-low dispersion) glass elements. The build quality is superb as expected from an L class lens. There's no wobbling whatsoever and the lens feels pleasantly sturdy. Rubberized focusing ring is very smooth and easy to grip. The lens offers a ring-type USM AF as well as full-time manual focusing mechanism. Users can switch between auto and manual focusing using an AF/MF switch on the side of the barrel. To help improve AF performance, Canon includes a focus distance limiter, which allows for two settings: 90cm (3ft) to infinity and 1.6m (5.24ft) to infinity. As with most modern Canon lenses, EF 135mm f/2.0L USM does not offer manual aperture control so aperture level has to be set directly from the camera. The lens sports true inner focus design, meaning that the lens cams do not extend during focusing.

Canon EF 135mm f/2.0L USM provides 1:5 maximum magnification at its minimum focusing distance of 90cm (3ft). The minimum aperture is f/22 and the filter size is 72mm (the front element of the lens does not rotate during focusing so you can attach a circular polarizer to the front mounting thread). The lens measures 8.25x11.2cm (3.2x4.4in) and weighs 750g (1.7lb).

 

Image

 

The lens is designed to fit Canon EF mount and on EF-S cameras with 1.6x crop factor the lens has field of view simiar to that on a 216mm lens of a full-frame body. The lens is compatible with Canon EF 1.4x II and EF 2x II Extenders as well as accepts Gelatin Filter Holder Adapters III and IV. The factory box includes Canon EF 135mm f/2.0L USM lens, front and rear caps, ET-78II lens hood, LP1219 soft case, manual and registration card.

 

Summary
Lens Composition 10 elements in 8 groups
Angular Field 18 degrees
Minimum Focus 90cm/3ft
Focusing Action AF/MF, USM
f-stop Scale f/2-f/32, camera-controlled
Filter Size 72mm
Lens Hood ET-78II (included)
Weight 750g/1.7lb
Dimensions 82.5x112mm/3.2x4.4"
Lens Case LP1219 (included)

 

Field Tests

The lens performed quite well in the field - images were pretty sharp from wide open through the rest of the tested aperture range, although images were a little bit softer around borders at f/2. AF was pretty fast and accurate most of the time, but did occasionally hunt at minimum focusing ranges - this does seems to be pretty common with most AF systems, so it doesn't necessarily have to be perceived negatively.

 

 

Vignetting @ f/2.0 - full frame vs 1.6x crop
Vignetting @ f/2.0 - full frame vs 1.6x crop

On an APS-C camera, vignetting was negligible throughout the tested aperture. Not so on a full-frame body where the lens did show moderate level of vignetting at f/2, which was reduced drastically once stopped down to f/2.8. As expected from a fixed focal lens, Canon EF 135mm f/2L USM did not exhibit any barrel distortion and managed to hold up the ground against flare but unfortunately it produced occasional (and minimal) purple fringing.

 

ISO 100, 1/4000, f/2, 135mm (100% crop)
ISO 100, 1/4000, f/2, 135mm (100% crop)
Sample images coming soon

 

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: Canon EF 135mm f/2.0L USM showed very solid performance in the lab. Center performance is outstanding from f/2.8, but even at f/2 quality remains at a decent level. Border performance follows similar trend - at f/2 quality is already good and it only improves with stopped down aperture. Overall performance peaks in the f/2.8-f/8 range. At its best, the lens is capable of producing outstanding 19in and very decent 24in prints, which is quite respectable even for a prime lens. Conclusion? While the results are not strictly speaking unique, quality (both build and image) fully supports the L designation that Canon gave to this lens (unfortunately, it also means paying a steep price for that quality).

 

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

 

Normalized raw MTF50 @ 135mm
Normalized raw MTF50 @ 135mm

 

Chromatic aberration on an APS-C camera was pretty minimal across the tested aperture range, averaging ~0.4px in the center and ~0.6px around corners with a wide open aperture and even less so when stopped down.

 

Image borders @ 135mm (100% crop): f/2.0 vs f/8
Image borders @ 135mm (100% crop): f/2.0 vs f/8

 

Canon FF: The lens continued to perform quite well on a full-frame Canon 5D. Center performance is outstanding straight from f/2. Border quality suffers a bit at f/2 but improves nicely with stopped down aperture and by f/5.6 reaches quite an impressive level. Conclusion? While the lens does give up some ground when it comes to border quality at f/2 on a full-frame camera, overall, it still remains a very solid performer.

 

Normalized raw MTF50 @ 135mm
Normalized raw MTF50 @ 135mm

 

CA was well under control with the full-frame camera as well, not exceeding ~0.6px around borders and ~0.4px in the center. Once stopped down to f/2.8 and beyond, CA becomes pretty much insignificant.

 

Image borders @ 135mm (100% crop): f/2.0 vs f/8
Image borders @ 135mm (100% crop): f/2.0 vs f/8

 

Alternatives

Assuming you are willing to give up a little bit in focal length, then one lens that immediately comes to mind is Canon EF 100mm f/2.8 USM Macro (review). While slightly slower then EF 135mm f/2L USM, this lens performs almost as well as its more expensive L cousin and at the same time offers life-size 1:1 macro capability in a package that goes for about half the price. For slightly longer focal length needs, you might want to consider Canon's EF 200mm f/2.8L USM (review) or Sigma's APO MACRO 150mm f/2.8 EX DG HSM. Both lenses exhibit decent overall performance and cost a few hundred dollars less.

 

Recommendation

Canon EF 135mm f/2L USM is a very solid lens with outstanding overall performance on both APS-C and full-frame cameras. Some vignetting with a full-frame body at wide open apertures and occasional purple fringing are things to be aware of here. Another point to consider is the price - at US$900 this is not the most expensive prime lens on the market but is not a bargain either. If you're looking for a fast telephoto and are not willing to sacrifice in lens build quality, then look no further. Otherwise, you might want to take a hard look at some other alternatives.