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Introduction

Canon EF 50mm f/1.2L USM, first released in mid 2006, is the fastest 50mm lens in Canon's arsenal. With the exception of Leica's Noctilux-M f/1.0 (which is not even available in SLR format) and Canon EF 50mm f/1.0L, which has been discontinued some time ago, Canon EF 50mm f/1.2L USM is the fastest 50mm production lens on the market. At about US$1,400 (as of April 2007), the lens is not the most expensive lens I've seen, but probably is not going to be the first choice for amateur and prosumer photographers.

The lens construction consists of 8 elements in 6 groups, including a single aspherical glass element. Conon EF 50mm f/1.2L USM is not the most compact or light 50mm lens - kudos to its ultra-wide aperture, the lens weighs 545g (19.2oz) and measures 85x85mm (3.4x3.4in). The minimum focusing distance is 45cm (1.48ft), giving a maximum magnification of 1:6.7. The lens accepts 72mm filters and has USM-type AF with full-time manual focusing. On APS-C type cameras with 1.6x crop sensors, the lens has field of view equivalent to that of an 80mm lens on a full-frame camera. And thanks to its ultra-wide aperture, the lens makes an excellent choice for portrait type work and low-light photography.

As expected from an L lens, the build quality is superb. The lens looks and feels very solid, with no wobbling inside whatsoever. The focus ring was smooth but the ring itself was slightly displaced, resulting in a minor shake during manual focusing - not sure if this is a common issue with this lens or a problem with the sample I tested. According to Canon's site, the lens has a special coating that minimizes ghosting and flare which could be quite pronounced with such wide aperture lenses (I can't confirm at this moment whether the coating is really different from one used on other L lenses or this is just another shtick to promote the lens).

 

Image

 

The factory box includes Canon EF 50mm f/1.2L USM lens, front and rear lens caps, ES-78 lens hood, LP1214 soft case, manual and registration card.

 

Summary
Lens Composition 8 elements in 6 groups
Angular Field 46 degrees
Minimum Focus 45cm/1.48ft
Focusing Action AF/MF
f-stop Scale f/1.2-f/16, camera-controlled
Filter Size 72mm
Lens Hood ES-78 (included)
Weight 545g/19.2oz
Dimensions 85.4x65.5mm/3.4x2.6"
Lens Case LP1214 (included)

 

Field Tests

The lens felt a bit bulky on my Digital Rebel and is most certainly the heaviest 50mm lens I tested to date. With its hood attached, the lens looks more like a medium telephoto then a standard lens.

The overall performance was quite good - EF 50mm f/1.2L USM was tack sharp in the center and around borders almost throughout the entire aperture range. I say almost because the lens seemed to struggle at f/1.2 (especially around borders). Border quality improved once stopped down and starting at f/2.8 the lens results were quite consistent. Of course comparing border quality at very wide apertures becomes rather hard because of the very shallow DOF you can achieve, especially when taking closeups.

As expected from a fixed focal lens, Canon EF 50mm f/1.2L USM showed no visible barrel distortion. Vignetting was somewhat on a higher end with wide open aperture, but becomes pretty minimal once stopped down to f/2.8. Considering that the tests were performed on a camera with 1.6x crop sensor, you should expect higher vignetting with full-frame dSLRs. The lens actually produced some purple fringing and was somewhat prone to flare with wide open aperture (there goes the theory about new coating Canon was promoting). On a positive side, the lens produced really smooth bokeh wide open.

 

ISO 100, 1/4000, f/1.2, 50mm (100% crop)
ISO 100, 1/4000, f/1.2, 50mm (100% crop)

 

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 50mm f/1.2L USM showed somewhat inconsistent results in the lab - the lens was tack sharp in the center from f/1.8, but the border quality did not really kick in until f/4 (the results from f/2.8 were quite good but not stellar). Furthermore, the image sharpness wide open at f/1.2 and to a lesser degree at f/1.4 was rather average. Not that the quality was glaringly bad, but not what I expected from a $1,400+ lens. Conclusion? Setting aside my shuttered expectations, this is still a really good lens capable of producing very good results from f/1,8. But then the whole point of getting such a fast lens was that you could use it wide open, wouldn't you say so?

 

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

 

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

 

The lens showed minimal levels of chromatic aberration around image center but did not fare as well around borders, where CA exceeded 1.5px with wide open aperture. Once stopped down to f/1.8 CA is reduced to about 1px but doesn't really go away even at smaller apertures.

 

Image borders @ 50mm (100% crop): f/1.2 vs f/8
Image borders @ 50mm (100% crop): f/1.2 vs f/8

Canon FF: Coming soon...

 

Alternatives

Naturally, the market is flooded with 50mm prime lenses. Canon alone makes three other 50mm variations: Canon EF 50mm f/1.4 USM (review), Canon EF 50mm f/2.8 Macro (review) and Canon EF 50mm f/1.8 II (review). Either of these three lenses is capable of producing very solid results, but from the image quality/build quality/overall cost perspective, the EF 50mm f/1.4 USM is probably a better alternative the its cheaper and slower cousins. Additionally, Sigma currently offers Sigma 50mm f/2.8 EX DG MACRO (review) lens, which you might consider to be an alternative to Canon's 50mm macro lens and less so to the 50mm f/1.2L one.

 

Recommendation

Canon EF 50mm f/1.2L USM is a very promising lens - it's one of the fastest prime lenses available for Canon's EF mount and is clearly targeted at photographers who require that extra f-stop and are willing to pay premium for it. However, the lens did not quite live to all my expectations. Overall performance was pretty solid from f/1.8 and on, but it was not extraordinary and certainly was not any better then what you could get from Canon's cheaper and slightly slower 50mm f/1.4 cousin. The border quality wide open leaves room for improvement, which is where my disappointment comes from. Of course if you plan to use the lens for portrait work then border sharpness would probably matter very little to you since the lens produces fantastic bokeh!