If we’re speaking in general terms, one zoom to rule them all would be a 24-70mm f/2.8L USM. Classed as a standard zoom lens, the 24-70mm focal length covers the most useful focal lengths, with a nice large aperture and high-quality optics. However, the f/2.8 version may be a touch too expensive for most or you simply don’t need the f/2.8 speed or width and want a smaller and more lightweight lens.
Thus, in steps the Canon EF 24-70mm f/4L IS USM, which is just as capable on full-frame and crop sensor camera bodies, with a few extra goodies on top of the f/2.8 version. These include image stabilization, a macro function, and of course a more affordable price point.
This means that if the f/4 version of the Canon 24-70mm can cut it in the optical department and with just as efficient workings, it’s a viable alternative to the f/2.8. Therefore, let’s have a closer look at this lens and see what it has to offer.
Design
The Canon EF 24-70mm f/4L IS USM is definitely more compact than its f/2.8 sibling, weighing a reasonable 600g. As previously mentioned, this lens works just as effectively on an APS-C camera body, providing an equivalent focal length of 38-112mm. This may feel a little bit front heavy on lighter weight camera bodies
As for the basic specifications, the optics are wrapped around 15 elements arranged in 12 groups. It features two ultra-low dispersion and two aspherical elements, plus fluorine and Super Spectra coatings.
The optical image stabilization system provides up to four stops of compensation along with a nine-blade rounded diaphragm. Upfront is a healthy-sized 77mm filter thread that is nonrotating.
The build quality is as you would expect from an L-series Canon lens. It is weather-proofed and feels rock-solid. The aperture and focus rings are rubberized and ridged for easy gripping.
Other exterior items on the lens barrel include the traditional distance scale, macro, AF/MF, and stabilization on an off switch. The stabilization system works on a basic level unless the camera body supports Normal IS and Panning IS modes.
The novel inclusion of the macro mode provides a close focusing distance of 20cm with a maximum magnification of 0.7x and a reproduction ratio of 1:1.4. When this mode is engaged, the zoom ring is turned to the ‘yellow’ section on the lens, from which focus can be fine-tuned, along with the lines indicated on the distance scale. This switch also activates the lens lock function which stops any zoom creep.
The lens comes with a lens cap, rear dust cap, and the petal-shaped Canon EW-83L lens hood. A departure from the style of lens hoods on older 24-70mm lenses, which was almost the length of the lens itself.
At this stage of the story, the EF 24-70mm f/4L IS USM covers all bases you would need from this type of zoom. Which brings us nicely to how the lens actually works in the field.
The Canon EF 24-70mm f/4L IS USM in Use
Focusing abilities on the Canon EF 24-70mm f/4L IS USM start with the focus ring, which has hard stops at either end. The ring-type Ultrasonic Motor (USM) is extremely quick to lock onto focus, with focus hunting only being experienced at very low light levels or in high contrast areas. But, these are areas most systems trip over when pushed to the extreme
As for general lens anomalies, chromatic aberration is handled extremely well with this lens, even when wide open. When shooting against a completely white background, there can be very small amounts of blue fringing, but nothing that post-processing can’t handle.
Vignetting is mild at f/4, but stopping down to f/5.6 alleviates the problem. As for barrel distortion, the effect is minimal at 24mm and completely disappears by the middle of the range.
The macro mode works extremely well and is a nice addition to this lens. The close focusing distance of 20cm provides clear detail, but it’s also advisable to use a tripod when shooting in macro to provide the most clarity.
Moving on to the quality of the background blur, bokeh effects are definitely creamy, provided by the nine-blade diaphragm. This may not be as smooth as the f/2.8 version, but unless you are comparing images side-by-side, you won’t be disappointed with the results. This means the lens is very adept at separating the subject from the background, working very well for the likes of portrait photography.
When it comes to sharpness levels, as predicted images are very sharp at 24mm f/4 in the corners and center and can’t be faulted from f/5.6 to f/8. From f/11 upwards, diffraction starts to take a toll, but the usable aperture ranges are extremely sharp where they are most needed in the middle of the focal range.
The results are the same with solid sharpness being seen at f/4, with the best result coming in from f/5.6 and upwards. At 70mm, sharpness is again very good at f/4, being excellent at f/5.6 and edges looking their best from f/8 onwards.
This all means that the 24-70mm f/4L generally delivers from the widest aperture and across the zoom range, with equally impressive results. Images are also produced with a good degree of contrast and vibrancy and the image stabilization can’t be faulted, providing some very useful low shutter speeds.
How Does It Compare?
The Canon EF 24-70mm f/2.8L II USM is an obvious comparison with the 24-70mm f/4L. Mainly because those Canon users who are eyeing up a 24-70mm will be looking at Canon’s own offerings first and if the f/4 version can deliver, just with a more narrow aperture.
When both lenses are set to f/4, they are almost comparable in sharpness and you have to be really pixel peeping to see the difference. The f/4 version benefits from having both image stabilization and a macro mode, but at least the f/2.8 has a dedicated lens lock switch.
However, the much higher price point of the f/2.8 version comes down to the added aperture width and optical quality that is needed at this range. This means for more general usage, the Canon EF 24-70mm f/4L IS USM is fantastic, but if you need that extra low-light capability and a more shallow depth of field, then the f/2.8 is the obvious option.
| Canon EF 24-70mm f/4L IS USM | Canon EF 24-70mm f/2.8L II USM | |
| Max Aperture | f/4 | f/2.8 |
| Image Stabilization | Yes | No |
| Aperture Blades | 9 rounded | 9 rounded |
| Weight | 600g | 805g |
Conclusion
There’s no denying that the Canon EF 24-70mm f/4L IS USM produces excellent images and really shows it’s worth on a full-frame body. The addition of image stabilization makes the lens a great operator in low-light conditions and it’s also very quick to lock into focus.
Image quality is excellent across the board, with very little lens anomalies, with the only negative being the small amounts of light falloff in the corners at 24mm and small amounts of edge softness from f/4-f/5.6.
The 24-70mm f/4L is clearly a great alternative to the f/2.8 version, but just like its sibling, it also has a high price tag. If you consider it’s fully rounded usefulness and years of quality images it can provide, then the price is insignificant.
This point is a no-brainer to the working photographer, but even to the enthusiast, the Canon EF 24-70mm f/4L IS USM will provide years of quality images and with the addition of image stabilization and the macro mode, makes this f/4 offering an excellent standard zoom for any occasion.
