Introduction

Canon EF 180mm f/3.5L Macro USM is one of five dedicated macro primes currently offered by the manufacturer. This is also one of the longest macro primes available in EF/EF-S mount that provides a 1:1 lifesize macro capabilities. The lens retails for ~US$1,300 (as of August 2008), making it also one of the more expensive macros on the market. At that price, the lens is clearly targeted at professionals and enthusiasts rather then mainstream users.

The optical construction of the lens consists of 14 elements in 12 groups, including 3 UD (Ultra Low Dispersion) elements. The lens features a floating system intended to improve optical characteristics of the lens at closeup distances. Combination of a large number of glass elements and pretty complex floating optical design result in a quite bulky form factor - the lens measures 83 x 187mm (3.2 x 7.3in) and weighs a whopping 1090g (2.4lb). The lens features a true inner focusing design, so its inner cams do not extend during focusing, leaving the total length constant at all times. Like with all of Canon's L grade lenses, the build quality of Canon EF 180mm f/3.5L Macro USM is very good - the barrel is made of hardened plastic, the focusing ring is fully rubberized and rotates with ease. There is no wobbling inside or out and the lens leaves impression of being quite sturdy.

Like all modern EF/EF-S lenses, Canon EF 180mm f/3.5L Macro USM implements a fully electronic aperture control, meaning that all aperture settings are set directly from the camera. The minimum supported aperture is f/32. The lens sports a ring-type USM auto focusing system, but also supports full-time manual focusing. The mode can be controlled using an AF/MF switch located on the side of the barrel. To improve the speed of auto-focusing, Canon incorporated a focusing limiter switch, which allows users to restrict the focusing distance. Two modes are available - mode 1 for focusing from 48cm to the infinity and mode 2 for focusing from 1.5m to the infinity. The focusing limiter switch is located on the side of the barrel, next to the AF/MF switch. The minimum focusing distance is 48cm (1.6ft). The front element of the lens does not rotate during focusing, allowing using circular polarizer filters. The filter size is 72mm.

 

Image

 

The factory box includes Canon EF 180mm f/3.5L USM lens, front and rear lens caps, LZ1324 semi-hard lens case, EW-78II lens hood, tripod collar, manual and warranty card. The lens is a traditional full frame lens, meaning that when used on an APS-C camera with 1.6x crop factor, the field of view of the lens will resemble that of a 288mm prime on a FF body. The lens is compatible with Canon's EF 1.4x and EF 2x Extenders, Extension Tubes EF 12 II and 25 II, as well as Gelatin Filter Holder Adapter IV.

 

Summary
Lens Composition 14 elements in 12 groups
Angular Field 13 degrees
Minimum Focus 48cm/1.6ft
Focusing Action AF/MF, USM
f-stop Scale f/3.5-f/32, camera-controlled
Filter Size 72mm
Lens Hood EW-78II (included)
Weight 1090g/2.4lb
Dimensions 82.5x186.6mm/3.2x7.3"
Lens Case LZ1324 (included)

 

Field Tests

Canon EF 180mm f/3.5L Macro USM looks, feels and behaves pretty much like any other Canon auto-focus lens. Did you really expect something else here? Well, this is obviously a generalization, but the lens really looks and feels like any other telephoto lens. But unlike other telephoto lenses of similar focal length, EF 180mm f/3.5L Macro USM feels much heavier and bulkier. The lens is actually heavy enough for Canon to include a tripod mount ring, which you will likely end up using when taking macro photos.

The overall performance of the lens in the field was quite decent. Image resolution seemed more or less uniform across the frame at wider apertures, although quality seemed to degrade somewhat at smaller apertures, especially beyond f/11. This is somewhat unusual, considering that most lenses typically show some weakness at wider and excel at medium apertures (diffraction typically kicks in around f/11 and beyond, thus degrading the image quality further).

One of the weakest points of the lens is the auto-focusing system. Despite Canon implementing a ring-type USM drive, the AF is quite slow. Not that it is hunting back and forth, it's just plain slow - if the lens is focused at infinity and you want to take a closeup shot, it takes practically forever for the lens to focus on the subject. Going from closeup to the infinity is not any better. Of course if you only interested in macro capabilities, then you are quite likely to use manual focusing and hence this issues with the AF is going to be less of a problem. There is even good news here for those of you who prefer manual focusing - the MF is quite accurate, with plenty of spacing, especially at closeup distances. The ring rotates ~250 degrees when going from the infinity to the minimum focusing distance.

 

ISO 400, 1/13, f/3.5, 180mm (Canon 5D)
ISO 400, 1/13, f/3.5, 180mm (Canon 5D)

 

As mentioned earlier, Canon EF 180mm f/3.5L Macro USM is one of the longest macro lenses capable of 1:1 lifesize magnification. There obvious benefits to that as well as some subtle disadvantages. On the positive side, you can achieve the lifesize macro at much longer distances - ever tried taking macro shots of a grasshopper at 20cm (the typical macro distance for 50-60mm macro lenses)? At the same time, with longer macro lenses would require you to leave more distance to the subject to achieve framing similar to that of shorter macros. The end result is that the 180mm lens will flatten the target subject significantly more then say a 50mm macro. This actually also means that it would be easier to render a more pleasing out-of-focus background with longer macro lenses simply because there will be less of it in the frame.

Setting the theory aside, Canon EF 180mm f/3.5L Macro USM showed pretty consistent performance at macro distances throughout the tested aperture range. The images above show that the center performance is practically identical. However, border performance is somewhat hard to eyeball here, due to the rather shallow DOF.

 

ISO 400, 1/50, f/3.5, 180mm (Canon 5D)
ISO 400, 1/50, f/3.5, 180mm (Canon 5D)

 

When shot with wide open aperture, the lens produced predominantly round, uniformly lit out of focus highlights. One can see occasional brightly lit outlining, but OOF highlights were mostly pretty neutral. There was no sign of double edging around OOF objects, but contrast transitions in the near and far OOF areas were somewhat on the harsher end.

 

Left: ISO 100, 1/400, f/3.5 Right: ISO 100, 1/80, f/8 (Canon 5D)
Left: ISO 100, 1/400, f/3.5 Right: ISO 100, 1/80, f/8 (Canon 5D)

 

Like most lenses, Canon EF 180mm f/3.5L Macro USM fell prone to flare in certain situations. As can be seen from the images above, with a strong direct light source (in this case sun) positioned near or directly within the frame, the lens produced quite noticeable glare. Wider apertures were more susceptible to this problem, with flare manifesting itself through a greatly reduced contrast across the entire picture frame. The amount of this artifact can obviously be reduced if a proper lens hood it used. Better yet, changing the image composition can completely eliminate flare.

 

Vignetting @ f/3.5 - full frame vs 1.6x crop (135mm)
Vignetting @ f/3.5 - full frame vs 1.6x crop (135mm)

 

The lens showed moderate degree of vignetting on a full frame body with wide open aperture. This is somewhat disappointing, considering the focal length and the relatively slow maximum aperture of the lens. Vignetting is still present at f/4 as well as at f/5.6, albeit in very small amounts. By f/8 vignetting is completely gone. On an APS-C type camera, the lens takes the full advantage of the smaller image sensor and shows basically no vignetting straight from f/3.5.

The lens showed decent handling of color - rendition was pretty accurate, although the palette remained somewhat on a warmer side, which is quite typical for Canon lenses. There were no obvious signs of color fringing or halation (axial CA) across the image frame and the lens showed no visible sign of barrel distortion and images carried more or less sufficient amounts of contrast when shot under normal conditions.

 

ISO 100, 1/800, f/3.5, 180mm (100% crop)
ISO 100, 1/800, f/3.5, 180mm (100% crop)

Lab Tests

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

 

Canon APS-C: The lens showed pretty good performance on an APS-C camera, backing the general trend observed in field tests - generally speaking, image quality was better at wider apertures, which is a welcome, but somewhat surprising development. Center performance is excellent straight from f/3.5 and border quality does not fall far behind. As the lens is stopped down towards f/11, image quality starts to degrade slightly. Nevertheless, the lens is capable of producing outstanding 16in prints throughout the tested aperture range and decent 24in prints at its widest aperture settings. Conclusion? Not too shabby, although quality per se is not really jaw-dropping. More importantly, how would the lens perform on a full frame body?

 

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

 

Normalized raw MTF50 @ 50mm
Normalized raw MTF50 @ 50mm

 

Chromatic aberration aberration on a Digital Rebel XTi was quite low by all standards. Center CA as well as border CA never exceeded ~0.5px across the tested aperture range.

 

Chromatic Aberration (APS-C) @ 50mm
Chromatic Aberration (APS-C) @ 50mm

Here are 100% crops taken with an APS-C type Canon Digital Rebel XTi comparing image borders at f/3.5 and f/8.

 

Image borders @ 180mm (100% crop): f/3.5 vs f/8
Image borders @ 180mm (100% crop): f/3.5 vs f/8

 

Canon FF: Overall performance on a full frame camera was somewhat similar to the performance the lens produced on an APS-C body. Center image quality remained excellent throughout the tested aperture range. Border performance lagged a little bit, but in the f/3.5 through f/8 range remains quite solid. Quality actually steadily degraded with stopped down aperture and by f/11 border performance started to show some weakness. Nothing major, but one can expect falling performance beyond f/11. Conclusion? Steady and pretty good overall performance. Not really spectacular resolution, but good enough for the majority of us.

 

Normalized raw MTF50 @ 50mm
Normalized raw MTF50 @ 50mm

 

The lens showed minor degree of pincushion distortion, however at ~0.3% distortion should not be visible in general type photography.

 

Distortion (FF) @ 50mm
Distortion (FF) @ 50mm

 

Chromatic aberration on a full frame Canon 5D was well under control, generally speaking hovering around ~0.5px throughout the aperture range and across the frame.

 

Chromatic Aberration (FF) @ 50mm
Chromatic Aberration (FF) @ 50mm

 

Here are 100% crops taken with an FF type Canon 5D comparing image borders at f/3.5 and f/8.

 

Image borders @ 180mm (100% crop): f/3.5 vs f/8
Image borders @ 180mm (100% crop): f/3.5 vs f/8

 

Alternatives

Assuming that you are looking for a telephoto macro lens, then your first choice should rest with Canon's EF 100mm f/2.8 Macro USM, which offers very good performance at a pretty affordable price. Outside of the Canon camp, you might want to consider Sigma's three telephoto macro lenses - Sigma APO Macro 180mm f/3.5 EX DG<, Sigma APO Macro 150mm f/2.8 EX DG and Sigma Macro 105mm f/2.8 EX DG. Another potential choice is Tamron's SP AF 180mm f/3.5 Di LD IF Macro or even SP AF 90mm f/2.8 Di Macro. If you are using an APS-C type camera with EF-S mount, then you might also want to consider Tokina's excellent AT-X AF PROD D 100mm f/2.8 Macro. One interesting choice, assuming you don't mind focusing manually (and assuming you can find this lens) is Voigtlander APO Lanthar 125mm f/2.5 SL. While discussing manual focus lenses, if you are willing to consider using an alternative mount lens, then your choices suddenly triple, even quadruple. Among the alternative mount lenses consider Leica's APO Macro Elmarit-R 100mm f/2.8, which would cost you about the same as a Canon EF 180mm f/3.5L Macro USM, but would offer significantly better performance and build quality. Carl Zeiss Makro-Planar T* 100mm f/2 ZF is another potential choice, although keep in mind that this lens offers only 1:2 macro capabilities. If you do need 1:1 macro, then consider the older, Contax branded version of this lens - Carl Zeiss Makro Planar T* 100mm f/2.8. Also don't forget to check out Nikon's AF Micro Nikkor 200mm f/4D ED IF and Micro Nikkor 105mm f/2.8 Ai-S. Oh yea, check also out Olympus OM 90mm f/2.

 

Recommendation

Canon EF 180mm f/3.5L Macro USM is a pretty solid lens. Image performance is pretty good, although not necessarily unique among telephoto lenses. The much cheaper Canon EF 100mm f/2.8 Macro USM can easily match its longer, more expensive brethren in this area. The lens shows good handling of color fringing, practically non-existent distortion, excellent build quality, semi-decent handling of vignetting. The only glaring weakness is the AF system, which is just too slow. Well, maybe flare handling as well, although it is doubtful other lenses would perform much better under such circumstances. One might wish an image stabilizer, but that feature will probably add another $300 to $500 to the price tag of an already expensive lens. So what's the problem then? It's the price tag for this lens. The combination of price/performance/handling of the lens is somewhat underwhelming. Ultimately, there are quite a few other lenses that will provide a better bang for the buck then Canon EF 180mm f/3.5L Macro USM.