Camera Accessories

A superb general-purpose lens, Canon's EF 24-105mm f/4 L IS USM is equally at home on the EOS 400D and the 'full frame' EOS 5D cameras, giving a focal length range equivalent to 38.4 to 168mm on the former. Compact for its specifications, it is relatively light and comfortable to use as well as being very well built. The lens barrel carries switches for IS (on/off) and AF/MF (Autofocus/Manual Focus). They are recessed into the lens barrel itself, which means you're less likely to re-set them inadvertently.

At no time in our tests did we experience any problems with incorrect settings.  With FTM (Full Time Manual) focusing, the manual focus ring can be fine-tuned quickly after autofocusing and you can also focus the lens with the camera switched off without re-setting the lens to manual focus.

As expected, this lens gives its best performance at middle apertures and mid-way through the zoom range. However, images are sharp at wide apertures and show only slight improvement as you stop down. Overall image quality is excellent, although we noticed a slight edge softening and vignetting with wide apertures at 24mm with our 5D shots (but not with the 400D).

Imatest testing showed the lens to be an excellent match for the 5D's sensor and chromatic aberration was negligible. However, resolution at 24mm was noticeably lower than at the higher focal length settings. In practice, pictures taken at the 24mm setting still looked very sharp, although we found slight softening towards the corners with the lens set at f/4.

Corner softening was also found with the lens at full aperture at longer focal lengths but sharpness returned quickly as the lens was stopped down. We estimate the optimum aperture range for this lens is between f/8 and f/16 for all focal lengths.

Barrel distortion was also visible at focal lengths between 24mm and about 40mm an slight pincushioning could be seen in shots taken at 105mm. Neither problem should affect general photography. Flare was very well controlled and colour and contrast reproduction were excellent.

Eight circular aperture blades give the lens attractive bokeh (defocused background/foreground blurring). The image stabiliser proved its worth with tele shots, especially in dull conditions, providing up to three stops of hand-holding latitude. In theory, you should be able to hand-hold the camera at shutter speeds as slow as 1/3 second with this lens. Whether you actually can will depend on your own capabilities - but we proved it was possible as shown in the sample shots below.

The IS function was also useful for close-ups, where a magnification of 0.23x is provided at 105mm. The silence and speed of the ring USM (Ultrasonic Motor) proved valuable for many shooting situations and the autofocusing control was very accurate. Finally, the weather-proof sealing was valuable for shooting in demanding situations.

The Canon EF 24-105mm f/4 L IS USM lens ships with a Canon EW-83H lens hood and a soft pouch for carrying the lens. It accepts 77mm filters, which makes sharing filters with many other Canon lenses easy. Internal focusing allows angle-critical filters to be used.

IMATEST GRAPHS

SAMPLE IMAGES

The lens performed impeccably in sub-zero conditions.

Shots taken at wide apertures show attractive bokeh.

The IS function allows hand-held shots to be taken at shutter speeds as slow as 1/4 second.

Maximum aperture: f/4 throughout zoom range

Minimum aperture: f/22
Lens construction: 18 elements in 13 groups
Minimum focus: 0.45 m
Filter size: 77mm
Dimensions (Diameter x L): 83.5 x 107 mm
Weight: 670 grams