Introduction

Released in mid 1997, Canon EF 24mm f/1.4L USM extended Canon's lineup of professional grade, ultra fast wide angle prime lenses (As of August 2007, this lineup also included EF 14mm f/2.8L USM and EF 35mm f/1.4L USM). Priced at about US$1,100 the lens is clearly targeted at professionals (and some well-off enthusiasts).

The optical construction of the lens consists of 11 elements in 9 groups, including a single aspherical glass element intended to reduce distortion and spherical aberration as well as a single UD lens element that corrects lateral chromatic aberration. The lens features floating element construction that improves corner-to-corner delineation. The build quality of the lens is very good as expected from a Canon 'L' class lens. There's no wobbling inside or outside and the lens feels pretty sturdy. Focusing ring is rubberized and is very smooth. The lens features internal focusing mechanism, meaning that the lens cams do not extend during focusing.

Canon EF 24mm f/1.4L USM offers ring-type USM auto as well as full time manual focusing which can be controlled by an AF/MF switch on the side of the barrel. Like with most modern Canon lenses, EF 24mm does not have a manual aperture ring, so aperture levels have to be controlled directly from the camera.

The lens is a bit 'bulky', measuring 84 x 77mm (3.3 x 3.1in) and weighing 550g (19.4oz). It has maximum magnification of 1:6 and the minimum focusing distance of 25cm (0.82ft). The minimum aperture is f/22 and the lens accepts 77mm screw-in type filters.

 

Image

The lens is designed to fit Canon's full-frame EF mount, so on APS-C type cameras with 1.6x crop sensors, the field of view of the lens will resemble that of a 38mm lens on a full-frame body. The lens is compatible with Canon's Extension Tubes EF 12 II and EF 25 II and accepts Gelatin Holder Adapters III and IV. The factory box includes Canon EF 24mm f/1.4L USM lens, front and rear caps, EW-83DII petal shaped lens hood, LP1214 soft case, manual and registration card.

 

Summary
Lens Composition 11 elements in 9 groups
Angular Field 84 degrees
Minimum Focus 25cm/0.82ft
Focusing Action AF/MF, USM
f-stop Scale f/1.4-f/22, camera-controlled
Filter Size 77mm
Lens Hood EW-83DII (included)
Weight 550g/19.4oz
Dimensions 83.5x77.4mm/3.3x3.1"
Lens Case LP1214 (included)

 

Field Tests

Canon EF 24mm f/1.4L USM produced solid results in the field. The lens was tack sharp in the center on both APS-C and FF cameras across entire tested aperture range. Borders were noticeably softer at wide aperture levels (f/1.4 especially), which should not come as a surprise since we're dealing with a super fast ultra wide lens here. AF system was reasonably fast and accurate. As is common with most Canon lenses, reproduced colors were somewhat on a warmer side.

 

Vignetting @ f/1.4 - full frame vs 1.6x crop
Vignetting @ f/1.4 - full frame vs 1.6x crop

 

The lens shows noticeable vignetting on a full frame camera at the widest aperture level, which is reduced by f/2 and becomes pretty much non existent once stopped down to f/2.8. The lens does not exhibit any noticeable vignetting straight from f/1.4. Unfortunately, the lens produced color fringing pretty much across the frame and fell prone to flare at f/1.4 (amounts of both color fringing as well as flare are reduced with stopped down apertures).

 

ISO 100, 1/4000, f/1.4, 24mm (100% crop)
ISO 100, 1/4000, f/1.4, 24mm (100% crop)
Canon EF 24mm f/1.4L 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: The lens showcased quite an impressive center performance almost throughout the entire tested aperture range. I say almost because at f/1.4 center performance is somewhat weaker but even then quality is not disastrous. Border performance is a different story here and the lens struggled at the widest aperture levels. From f/1.4 through f/2, border quality is pretty dismal. However, once stopped down to f/2.8, border performance improves and reaches pretty solid levels, remaining on a consistent level throughout the rest of the aperture. At its peak around f/5.6-f/8, the lens is capable of producing outstanding 16in and decent 19in prints. Conclusion? The lens is clearly capable of producing pretty decent results, but not at its widest supported aperture level. Still. the overall results can be considered decent for such an ultra wide, ultra fast prime lens.

 

MTF50 (Line Width/Inch on the Print) @ 24mm
MTF50 (Line Width/Inch on the Print) @ 24mm

 

Normalized raw MTF50 @ 24mm
Normalized raw MTF50 @ 24mm

 

Chromatic aberration was rather on a high level with this lens on an APS-C camera. CA averages ~0.9px in the center and ~1.6px around borders at f/1.4. Once stopped down CA is reduced significantly in the center, but still remains pretty high around borders, where it averages ~1.1px throughout the rest of the aperture range.

 

Image borders @ 24mm (100% crop): f/1.4 vs f/8
Image borders @ 24mm (100% crop): f/1.4 vs f/8

 

Canon FF: Canon EF 24mm f/1.4L USM continued to show quite impressive performance in the center, where it excelled pretty much throughout the tested aperture. But like with the APS-C camera, the lens continued to struggle around borders, especially at the widest aperture levels from f/1.4 through f/2. Border quality in this aperture range was rather mediocre. The good news is that border performance improves once stopped down to f/2.8. Conclusion? Well, while the border performance suffers at the widest aperture levels, at least the lens shows consistent performance across aperture range on both APS-C and FF cameras.

 

Normalized raw MTF50 @ 24mm
Normalized raw MTF50 @ 24mm

The lens managed to held up better against CA on a full frame camera. CA did not exceed ~0.4px in the center and ~0.7px around borders across the tested aperture range. For an ultra-wide prime lens this level of CA can be considered more or less OK.

 

Image borders @ 24mm (100% crop): f/1.4 vs f/8
Image borders @ 24mm (100% crop): f/1.4 vs f/8

 

Alternatives

Currently Canon offers a number of wide angle lenses but only EF 35mm f/1.4L USM (review) offers similarly fast aperture. And unfortunately, most of Canon's other alternatives while cheaper, do not offer any improvement in performance, especially around borders. Having said that, you might still want to take a look at Canon EF 20mm f/2.8 USM (review) and Canon EF 28mm f/1.8 USM. However, if you're serious about finding a wide angle prime with best possible border performance, you might need to expand your search to alternative lenses such as Carl Zeiss and Leica that can be adopted to your favorite Canon camera using readily available adapters.

 

Recommendation

Canon EF 24mm f/1.4L USM is a solid wide angle prime that excels once stopped down to f/2.8 and beyond. The weakness in border performance at wide aperture levels should no longer surprise anyone - there are very few fast wide angle lenses that can showcase consistently high performance across the entire aperture range. Vignetting on full-frame body as well as somewhat high level of CA at wide apertures are things to be aware as well. Price is another thing to consider here - at US$1,100 the lens remains within the reach of serious amateurs (and professionals obviously), but it is certainly no bargain. However, considering that there are not that many alternatives to choose from (that are both producing better image quality as well as are priced more aggressively), Canon EF 24mm f/1.4L USM should probably remain high on your shopping list, especially if you are looking for a dedicated fast wide angle prime.