Introduction

Canon EF 70-200mm f/4L IS USM is the latest addition to Canon's range of 70-200mm telephoto zooms and fills in the whole in Canon's lineup previously consisting of two faster f/2.8 variants (EF 70-200mm f/2.8L IS USM and EF 70-200mm f/2.8L USM) and another f/4 version (EF 70-200mm f/4L USM). Released in 2006, Canon EF 70-200mm f/4L IS USM is currently (as of February 2008) priced at about US$1,000, or almost US$500 more then the most value oriented EF 70-200mm f/4L USM. Still, the lens remains within reach of serious amateurs and obviously professionals and is quite popular these days.

The optical construction of the lens consists of 20 elements in 15 groups, including a single CaF2 and two US (Ultra low Dispersion) glass elements. Like all of Canon's L series lenses, Canon EF 70-200mm f/4L IS USM sports a very sturdy construction with no wobbling inside or out and weather sealed shell. The lens features a true internal focusing mechanism, so the lens does not extend during zooming, keeping the overall length constant at all times. Canon incorporated its third generation image stabilization technology into the lens which offers photographers a whopping four stops of correction for lens shake (or at least that is what Canon claims). The IS system can be operated in two modes: mode 1 compensates for both horizontal and vertical shake, while mode 2 compensates only for vertical shake, which is suitable for action photography. And unlike the first generation IS systems, the new system can detect static/tripod mounting and automatically switch itself off (temporarily).

The lens features a ring-type USM AF system along with a full-time manual focusing system (controlled by an AF/MF switch on the side of the barrel). Because of the built-in IS, the lens is slightly heavier when compared to its non IS variant, measuring 76 x 172mm (3 x 6.8in) and weighing 760g (26.8oz). The minimum focusing distance is 1.2m (3.94ft) and the minimum supported aperture is f/32. The lens accepts 67mm screw-in type filters.

 

Image

 

The factory box includes Canon EF 70-200mm f/4L IS USM lens, front and rear caps, ET-74 lens hood, LZ1224 lens pouch, manual and registration card. Unfortunately, the lens does not include a tripod collar. Canon EF 70-200mm f/4L IS USM is compatible with Canon's EF 1.4x II and EF 2x II Extenders, which increase the focal reach of the lens at the expense of its speed. You can use gelatin filters assuming you attach optional Gelatin Filter Holder Adapter III or IV. Like its three other variants, Canon EF 70-200mm f/4L IS USM is designed for full frame cameras, so on an APS-C body its field of view resemble that of a 112-320mm telephoto zoom on a full frame body.

 

Summary
Lens Composition 20 elements in 15 groups
Angular Field ~34-12 degrees
Minimum Focus 1.2m/3.94ft
Focusing Action AF/MF, USM
f-stop Scale f/4-f/32, camera-controlled
Filter Size 67mm
Lens Hood ET-74 (included)
Weight 760g/26.8oz
Dimensions 76x172mm/3x6.8"
Lens Case LZ1224 (included)

 

Field Tests

Canon EF 70-200mm f4L IS USM produced showcased very good characteristics in the field. Images were razor sharp straight from the widest aperture and throughout the zoom range. Visually, both center as well as border quality remained on about the same level with basically no noticeable degradation even around extreme corners.

The lens looks, feels and handles very much like its older, non IS version. The IS system does certainly help when shooting off hand, although as any IS system it has its own limitations - as you move towards 200mm, it becomes harder for IS to compensate internal shake. Thus it is probably a good idea to try to rely on a tripod, especially when shooting with longer exposures. AF is pretty fast and accurate in most situations (the lens AF system hunts for focus occasionally in the dark, but low light photography has always been challenging to most AF systems, so there's nothing extraordinary here).

 

Vignetting @ f/4 - full frame vs 1.6x crop (70mm)
Vignetting @ f/4 - full frame vs 1.6x crop (70mm)

 

Vignetting @ f/4 - full frame vs 1.6x crop (200mm)
Vignetting @ f/4 - full frame vs 1.6x crop (200mm)

 

The lens showed negligible amount of vignetting on a full frame body at 70mm with wide open aperture, which is all but gone by f/5.6. Amount of vignetting drops further as you move towards the longer end of the zoom range, and at 200mm vignetting is not even noticeable throughout the aperture range. And on an APS-C body the lens shows practically no vignetting to start with throughout the zoom and and all aperture ranges. The lens demonstrated outstanding color reproduction, with images carrying satisfactory amount of contrast and no visible color fringing across the zoom range. As it is expected from a telephoto zoom, Canon EF 70-200mm f/4L IS USM did not show any noticeable distortion throughout the zoom range. The lens also help up against flare even with wide open apertures.

 

ISO 100, 1/1600, f/4, 70mm (100% crop)
ISO 100, 1/1600, f/4, 70mm (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: Canon EF 70-200mm f/4L IS USM showed excellent results on an APS-C body. The lens excelled at 70mm, where both center as well as borders remained tack sharp pretty much throughout the tested aperture range. Well, technically speaking, quality degraded a bit towards f/11, but still remains quite usable. As you move towards the longer end of the zoom range, quality starts to deteriorate somewhat and by 200mm the lens is not longer a stellar performer. Quality degradation becomes especially noticeable around borders. Still, even at 200mm, the lens shows very solid center performance and decent, but not breathtaking border performance. At its peak in the f/4-f/5.6 range (70mm to about 135mm), the lens is capable of producing outstanding 19in and very decent 24in prints, which would be quite competitive, even when compared to dedicated telephoto primes. Conclusion? In how many cases would you claim that your zoom can perform as well as a dedicated prime? With Canon EF 70-20mm f/4L IS USM, you will be able to (to some extent of course) make such claims.

 

MTF50 (Line Width/Inch on the Print) @ 70mm
MTF50 (Line Width/Inch on the Print) @ 70mm

 

Normalized raw MTF50 @ 70mm
Normalized raw MTF50 @ 70mm

 

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

 

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

 

MTF50 (Line Width/Inch on the Print) @ 200mm
MTF50 (Line Width/Inch on the Print) @ 200mm

 

Normalized raw MTF50 @ 200mm
Normalized raw MTF50 @ 200mm

 

Chromatic aberration was well under control with this lens. CA did not exceed ~0.5px in the center and ~0.8px around borders throughout the zoom and across the aperture range. In general, CA was a bit higher towards 200mm (both in the center as well as around borders), but even there it was not disastrous.

 

Chromatic Aberration (APS-C) - Center
Chromatic Aberration (APS-C) - Center

 

Chromatic Aberration (APS-C) - Borders
Chromatic Aberration (APS-C) - Borders

 

Here are 100% crops takes with an APS-C camera (Digital Rebel XTi), comparing image borders at 70mm, 100mm and 200mm.

 

Image borders @ 70mm (100% crop): f/4 vs f/8
Image borders @ 70mm (100% crop): f/4 vs f/8

 

Image borders @ 100mm (100% crop): f/4 vs f/8
Image borders @ 100mm (100% crop): f/4 vs f/8

 

Image borders @ 200mm (100% crop): f/4 vs f/8
Image borders @ 200mm (100% crop): f/4 vs f/8

 

Canon FF: Canon EF 70-200mm f/4L IS USM continued its outstanding performance streak even with a full frame camera. The lens produced very balanced balanced results across the zoom range, but especially excelled around 70mm. Center image quality as well as border image quality remained on a very high level here throughout the aperture range, although like with an APS-C body, performance degraded a little bit towards f/11. Image center remains tack sharp throughout the zoom range, but as you move towards 200mm image quality around borders starts to degrade and at 200mm there is a slight gap between center and border performance. Conclusion? With very solid performance pretty much throughout the zoom range, Canon EF 70-200mm f/4L IS USM is one very impressive lens.

 

Normalized raw MTF50 @ 70mm
Normalized raw MTF50 @ 70mm

 

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

 

Normalized raw MTF50 @ 200mm
Normalized raw MTF50 @ 200mm

 

CA remained well under control on a full-frame body as well. As with an APS-C body, CA was slightly higher towards the longer end of the zoom range. Center CA did not exceed 0.5px (and was actually lower at 70mm) and border CA hovered around ~0.7px throughout the most of the zoom range. Quite manageable and nothing to worry about.

 

Chromatic Aberration (FF) - Center
Chromatic Aberration (FF) - Center

 

Chromatic Aberration (FF) - Borders
Chromatic Aberration (FF) - Borders

 

Here are 100% crops takes with an full-frame camera (Canon 5D), comparing image borders at 70mm, 100mm and 200mm.

 

Image borders @ 70mm (100% crop): f/4 vs f/8
Image borders @ 70mm (100% crop): f/4 vs f/8

 

Image borders @ 100mm (100% crop): f/4 vs f/8
Image borders @ 100mm (100% crop): f/4 vs f/8

 

Image borders @ 200mm (100% crop): f/4 vs f/8
Image borders @ 200mm (100% crop): f/4 vs f/8

 

Alternatives

As mentioned earlier, Canon currently manufactures 3 other 70-200mm lenses. Naturally, if you're looking for an alternative to EF 70-200mm f/4L IS USM, this is the place to start your search. Assuming you don't require an IS system, you might want to take a look at EF 70-200mm f/4L USM or its faster variant EF 70-200mm f/2.8L USM. If you do need an IS and want a faster speed, then EF 70-200mm f/2.8L IS USM is worth taking a look. All four of Canon's 70-200mm lenses showcase outstanding image performance and build quality. If you're willing to tolerate a slightly slower speed in exchange for an extra focal length reach, Canon's EF 70-300mm f/4-5.6 IS USM is another worthy candidate. Outside of the Canon camp, take a look at Sigma's 70-200mm f/2.8 II EX DG MACRO HSM as well as Tamron's SP AF 70-200mm f/2.8 Di LD (IF) Macro. For a side by side comparison of the 70-200mm lenses, you might want to check out the 70-200mm Challenge.

 

Recommendation

Canon EF 70-200mm f/4L IS USM is clearly one of the best EF mount telephoto zoom lenses available on the market. The lens shows outstanding image quality with particular strength in the 70-135mm range. Combine this with excellent build quality, well controlled artifacts such as vignetting and chromatic aberration, and you get a winner on your hands. Granted, Canon offers a full lineup of 70-200mm lenses in its modern portfolio, including a somewhat cheaper, non IS version of the lens (EF 70-200mm f/4L USM), so I can't really claim that this lens has no competition. And at almost US$1,000, the lens seems a bit expensive, but then again, you have to pay for the quality and price/performance ratio is still pretty favorable here. The bottom line is that you can't seem to go wrong with EF 70-200mm f/4L IS USM.