Introduction

Released back in mid 1991, Canon EF 100mm f/2 USM along with its 85mm f/1.8 cousin is one of the most affordable medium telephoto lenses in Canon's modern arsenal. Priced at ~US$350 (as of October 2007), it remains within the reach of amateur photographers looking for a portrait type lens.

The optical construction of the lens consists of 8 elements in 6 groups. Build quality is decent but not spectacular - outer barrel is made of plastic with metal mount. The focus ring is rubberized and feels smooth. The lens does not have a dedicated aperture ring and like with most modern Canon lenses, aperture is set electronically from the camera. Canon EF 100mm f/2 USM sports a true inner focusing mechanism, meaning that the lens cams do not extend during focusing, hence no wobbling inside. The lens offers ring-type USM AF as well as full time manual focusing systems. The focusing mode is controlled by an AF/MF switch on the side of the body. The minimum focusing distance is 90cm (3ft), while the minimum supported aperture is f/22. The lens accepts 58mm screw-in type filters. The lens weighs 460g (1lb) and measures 75 x 73mm (3 x 2.9in).

Image

Canon EF 100mm f/2 USM is a full-frame lens, so if you use it on an APS-C type camera with 1.6x crop factor, the field of view of the lens will be equivalent to that of a 160mm lens on a full-frame body. The factory box includes Canon EF 100mm f/2 USM lens, front and rear caps, manual and registration card. The lens is compatible with optional LP1014 soft case and ET-65III lens hood (also optional).

 

Summary
Lens Composition 8 elements in 6 groups
Angular Field ~24 degrees
Minimum Focus 90cm/3ft
Focusing Action AF/MF, USM
f-stop Scale f/2-f/22, camera-controlled
Filter Size 58mm
Lens Hood ET-65III (optional)
Weight 460g/1lb
Dimensions 75x73mm/3x2.9"
Lens Case LP1014 (optional)

 

Field Tests

Canon EF 100mm f/2 USM produced outstanding results in the field, with excellent overall image sharpness across the frame and throughout the aperture range (on both FF and APS-C cameras). Performance was on the level of a best L lens, which by itself came as a major surprise considering that this is one of the least expensive medium telephoto primes in Canon's modern lineup. As a matter of fact, I kept comparing EF 100mm f/2 to EF 135mm f/2L which I tested a few weeks ago, and with the exception of the build quality, overall performance comparison stacked up quite favorably.

AF system is pretty fast, quiet and more importantly quite accurate, although the motor would hunt occasionally, mostly at close focusing distances. Since the lens is pretty light and compact, shooting from hand did not pose much of a problem.

 

 

Vignetting @ f/2 - full frame vs 1.6x crop
Vignetting @ f/2 - full frame vs 1.6x crop

 

Vignetting on a full frame body was pretty minimal at f/2 and non-existent once stopped down to f/2.8 and beyond. The lens shows no signs of vignetting on an APS-C type camera straight from f/2. Color fringing is very minimal, occasionally popping up around corners. Images show excellent contrast throughout the frame with pretty accurate overall color balance. The lens did not exhibit any noticeable barrel distortion, which does not come as a surprise in a medium telephoto lens, and held up nicely against flare, even at its widest aperture level.

 

 

ISO 100, 1/1600, f/2, 100mm
ISO 100, 1/1600, f/2, 100mm
Canon EF 100mm f/2 USM image gallery...

 

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 100mm f/2 USM produced outstanding performance on an APS-C type body. Image center was outstanding straight from f/2 and remained on a consistently high level through the rest of tested aperture range. Border quality closely followed center performance with excellent results throughout the aperture range (well, borders got a tidbit softer by f/11). Overall results are very balanced across the frame, which is a very desirable characteristic in any lens. At its peak, from f/2.8 through f/8, the lens is capable of producing outstanding 16in and very decent 24in prints. Conclusion? The lens shows very impressive results, easily putting it in the top quartile of medium telephoto lenses.

 

 

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 was pretty low, even for a medium telephoto lens. CA never exceeded 0.4px in the center and was quite manageable around borders as well, averaging ~0.5px.

 

 

Image borders @ 100mm (100% crop): f/2 vs f/8
Image borders @ 100mm (100% crop): f/2 vs f/8

 

Canon FF: The lens continued to show outstanding performance on a full frame body as well, with exceptionally good center performance and very solid border performance throughout the aperture range. Like with an APS-C camera, results are pretty balanced, although center quality does degrade a little bit towards f/11 (it's pretty marginal). Conclusion? Overall performance is simply top-notch, rivaling any medium telephoto you can find on the market these days.

 

 

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

 

CA on a full frame Canon 5D was pretty minimal, averaging ~0.25px in the center and ~0.3px around borders across the tested aperture range.

 

 

Image borders @ 100mm (100% crop): f/2 vs f/8
Image borders @ 100mm (100% crop): f/2 vs f/8

 

Alternatives

Canon currently offers a couple of medium telephoto lenses that you might want to consider as alternatives to EF 100mm f/2 USM. The first one worth taking a look at is EF 85mm f/1.8 USM (review), which offers excellent image quality across the frame and aperture range at a pretty affordable price.If you're looking for a super fast medium telephoto, and are willing to shed US$1,300+, then take a look at Canon EF 85mm f/1.2L Mk2 USM (review), which offers pretty solid overall performance with somewhat soft borders at wider aperture settings. For those of you willing to consider a slightly longer focal length, Canon EF 135mm f/2L USM (review) offers excellent and very balanced performance at a more or less affordable price. Outside of the Canon camp, you might want to consider Sigma 105mm f/2.8 EX DG Macro.

 

Recommendation

Canon EF 100mm f/2 USM is an outstanding medium telephoto lens that would rival even the most expensive L glass. The lens practically has no weaknesses - excellent image quality, low level of artifacts, fast and accurate AF system, pretty affordable price. Build quality, while not as good as with L quality lenses, is not too bad either. So what else is there to say? Grab one end enjoy!