Introduction

Canon EF 100mm f/2.8 USM Macro, first released in early 2000, is one of five macro lenses in Canon's arsenal. Priced at about US$450 (as of June 2007) the lens is not the cheapest EF (or EF-S) mount lens available on the market but is nevertheless affordable for mainstream consumers.

The optical composition of the lens consists of 12 elements in 8 groups, with a 3-group floating system that is designed to improve delineation at various focusing distances. The build quality is very similar to that of an average Canon consumer-grade level - the barrel is made of hardened plastic with rubberized focusing ring. The lens does not offer manual aperture control, meaning that the aperture has to be set from the camera. Canon EF 100mm f/2.8 USM Macro sports a true inner focusing (the lens does not extend during focusing and hence no wobbling in the lens) and includes both AF (ring-type USM) as well as full time manual focusing system, which can be controlled by an AF/MF switch on the side of the barrel.

The lens offers 1:1 (lifesize) magnification at its minimum focusing distance of 31cm (1ft). It also offers focus distance limiter that helps optimize AF performance for closeup and long-range photography (the limiter allows switching between two focusing distances: 31cm (1ft) to infinity and 48cm (1.57ft) to infinity). The minimum aperture is f/32 and filter thread size is 58mm. The lens is relatively compact (for a telephoto lens that is), measuring 7.9x11.9cm (3.1x4.7in) and weighing 600g (21.1oz).

 

Image

 

The lens is designed for EF mount and on EF-S cameras with 1.6x crop ratio it has a field of view similar to that of a 160mm lens on a full-frame SLR. The lens accepts optional EF-67 lens hood and is compatible with Canon's EF 12 II and 25 II Extension Tubes. If you plan to use gelatin filters, you need to obtain optional Gelatin Filter Holder Adapter III or IV. You can also use optional Tripod Mount Ring B that attaches to the rear of the lens to achieve better balancing when shooting with a tripod. The factory box includes Canon EF 10mm f/2.8 USM Macro lens, front and rear caps, manual and registration card.

 

Summary
Lens Composition 12 elements in 8 groups
Angular Field 24 degrees
Minimum Focus 31cm/1ft
Focusing Action AF/MF, USM
f-stop Scale f/2.8-f/32, camera-controlled
Filter Size 58mm
Lens Hood ET-67 (optional)
Weight 600g/21.1oz
Dimensions 79x119mm/3.1x4.7"
Lens Case LP816 (optional)

 

Field Tests

The lens performed quite well in the field, with sharp results across pretty much entire tested aperture range (well, maybe a tidbit softer around borders at f/2.8, but only a bit). At f/2.8, the lens produced very pleasant bokeh at macro ranges. Inner focusing most certainly is another reason to like this lens when doing macro photography. AF was very fast in telephoto shooting but did hunt occasionally in closup scenarios. As is typical of most Canon lenses, EF 100mm f/2.8 USM Macro produced somewhat warmer color palette - something that can be easily fixed during post processing step, so there's nothing to worry about here.

 

Vignetting @ f/2.8 - full frame vs 1.6x crop
Vignetting @ f/2.8 - full frame vs 1.6x crop

 

As expected from a prime telephoto lens, Canon EF 100mm f/2.8 USM Macro showed no visible distortion. Vignetting was very minimal at f/2.8 on a full-frame Canon 5D and non existent on Canon 400D (Digital Rebel XTi). Chromatic aberration and flare were well under control with both full-frame and APS-C bodies.

 

ISO 100, 1/500, f/2.8, 100mm (100% crop)
ISO 100, 1/500, f/2.8, 100mm (100% crop)
Sample images coming soon...

 

LabTests

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 performed quite well on an APS-C camera, with very balanced overall results. Sharpness in the center is pretty good starting at the widest aperture setting and improves slightly once stopped down, peaking in the f/4-f/5.6 range. Border quality is reasonably good at f/2.8 and also improves with stopped down aperture. At its peak around f/4-f/5.6, the lens is capable of producing outstanding 19in and decent 24in prints. Conclusion? The results of the tests support widely believed opinion that Canon EF 100mm f/2.8 USM is a hidden L lens. The fact that the lens also offers lifesize macro capabilities only sweetens the deal.

 

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

 

Normalized raw MTF50 @ 100mm
Normalized raw MTF50 @ 100mm

 

Chromatic aberration (fringes of color at sharp contrast transitions) was quite moderate: CA averaged ~0.6px both in the center and around borders across the tested aperture range.

 

Image borders @ 100mm (100% crop): f/2.8 vs f/8
Image borders @ 100mm (100% crop): f/2.8 vs f/8

Canon FF: The lens continued to show consistent and more importantly solid results with a full-frame Canon 5D. Center performance was quite even throughout the tested aperture. Like with an APS-C camera, border quality at f/2.8 was pretty decent (but not exceptional) and improved with stopped down aperture. The overall results, while not unique, are quite impressive. Conclusion? Consistent results with no significant fall-offs in sharpness on both APS-C and FF bodies should clearly influence anyone to consider this lens for his/her lens set.

 

Normalized raw MTF50 @ 100mm
Normalized raw MTF50 @ 100mm

 

CA is somewhat higher with a full-frame body and at f/2.8 it averaged ~0.9px around corners and ~0.6px in the center. CA is reduced slightly once stopped down to f/4 and remains at ~0.5px (around borders) throughout the rest of the aperture range. At this level CA still remains quite manageable and considering that CA can be easily fixed during post-processing does not pose any problems from my perspective.

 

Image borders @ 100mm (100% crop): f/2.8 vs f/8
Image borders @ 100mm (100% crop): f/2.8 vs f/8

 

Alternatives

Assuming that you are looking for a macro lens and own an APS-C camera, you might want to consider Canon's excellent EF-S 60mm f/2.8 Macro USM. This lens packs excellent image quality at a very affordable price. Canon also offers EF 180mm f/3.5L Macro USM, which is one of the longest macro lenses available in the EF mount. Unfortunately, with the exception of longer focal length, this lens does not offer much when compared to EF 10mm f/2.8 USM Macro. It is almost three times as expensive, is slightly slower and its performance is not any better. If you're willing to switch to Sigma camp, then you might want to take a look at Sigma 70mm f/2.8 EX DG Macro and Sigma 105mm f/2.8 EX DG Macro. Finally, you might also want to examine Tokina's AF 100mm f/2.8 Macro.

 

Recommendation

Canon EF 100mm f/2.8 USM Macro is one of the best lenses in Canon's modern portfolio. The lens exhibits very even performance across pretty much entire aperture range on both APS-C and full frame cameras. With no major artifacts to speak about, decent build quality and inner focusing mechanism, as well as very reasonable price tag, this is the lens to own for macro and telephoto photography.