Canon EF 24-70 mm f/4 l IS USM: a surprising new model in Canon’s advanced L-series.

Surprising, because the zoom range and the largest aperture is similar to the popular Canon 24-105 mm f/4 IS USM. The optical system includes two aspherical elements and two UD (Ultra low Dispersion) lenses. A fluorine coating on the front and rear minimizes the amount of dirt, dust and fingerprints – and contributes to a superior picture quality and reduces the need for cleaning. The new macro function enables you to take pictures with a maximum magnification of 0.7 x – so you do not need to take a special macro lens. We previously reviewed the Canon 24-70 mm f/4 on a Canon 5D MK3, but how does it perform on a camera with an APS-C sensor such as a Canon 7D, Canon 70D or as in our case a Canon 650D?

EF-24-70mm-f4L-IS-USM-FRA

Field of view Canon 24-70 mm f/4 @ 24 mm	FOV Canon 24-70 mm f/4 @ 70mm
Today it seems that many sports choose the largest possible zoom range. On the other hand, there are more and more photographers who try to distinguish themselves by only using lenses with a fixed focal length. The Canon 24-70 mm f/4 IS offers a zoom range of almost 3 x, with a view angle on an APS-C camera that corresponds to the angle of view of a 38-112 zoom lens on a camera with a full frame sensor. For a large group of landscape, street, or holiday photographers, that is more than sufficient. You can even shoot a nice full screen portrait, sharp from nose to ear, with it.
Construction and autofocus
The Canon EF 24-70 mm f/4 l IS USM is built as expected for a Canon L lens. Like a tank. Yet this lens with a weight of 600 grams is clearly lighter than its Canon brand-mates: 10% lighter than the Canon 24-105 mm and up to 30% lighter than the Canon 24-70 mm 2.8 II. That’s very nice. The outside of the Canon 24-70 mm f/4 has a high-quality coating with a leather texture, and it is, like all Canon L lenses, dust-and moisture-proof. The lens gets longer as you zoom. Especially during the use of the macro mode that is something to be reckoned with, because the front lens is very close to the subject. On the lens are 3 buttons: AF/MF, IS on/off and a combined macro/lock button with which you can put the lens in macro mode, or can lock to protect it from shocks while traveling.	{insertgrid ID = 289}
Image stabilization
The Canon EF 24-70 mm f/4 l IS USM has a newly designed IS-system that throughout the entire zoom range delivers sharper photos. The Hybrid IS compensates for angular distortions and tilting movements and even during macro photography, delivers sharper close-ups. The image stabilization of the Canon 24-70 mm f/4 is better than the image stabilization of the Canon 24-105 mm f/4. We reviewed the image stabilization of the Canon 24-70 mm f/4 on a Canon 5D MK3 (and the 24-105 mm on a Canon 5D MK2) at a focal length of 70 mm. In that test, we got with the Canon 24-105 mm f/4 an actual profit of 3 stops: the resolution of a recording made without IS at a shutter speed of 1/30 is equal to the sharpness of a shot take by hand with IS and a shutter speed of 1/4. With the naked eye that slight decrease in resolution is not immediately visible. When you take this into account then you can even speak of a profit of 4 stops. In the test of the Canon 24-105 mm f/4 the image stabilization is rated by eye and a profit of 2.5 stops is observed.
Macro Canon 24-70 mm f/4 IS
Canon 24-70 mm f/4 IS @ macro 70mm, f/11
On the Canon 24-70 mm f/4 IS, there is a macro button, with which you still can focus on shorter distances. Formally, this is not a macro lens because the lens reaches no 1:1 image yardstick/magnification factor. Even so, you make in practice many “macro images” with a magnification ratio of less than 1. The macro mode is one of the most important advantages of the Canon 24-70 mm f/4 IS. The picture quality is very good, especially after a couple of stops stopping down.
Resolution
The sharpness at maximum aperture is already high and remains that way to aperture 11. The sharpness at the edges and corners is a little below the sharpness in the center. The Canon 24-105 mm f/4 IS, as we saw in our testing, at maximum aperture in the corners yields a lower sharpness than the Canon 24-70 mm f/4. In terms of image quality, the Canon EF-S 17-55 mm f/2.8 IS USM is equivalent to the Canon 24-70 mm f/4 on a camera with an APS-C sensor. The Canon 24-70 mm f/4 loses in terms of sharpness to the more expensive Canon 24-70 mm f/2.8 II, “You get what You pay for.”.
Vignetting
This Canon 24-70 mm f/4 IS lens is designed for use on a camera with a full frame sensor. Then vignetting is visible at all focal lengths if you use this lens at f/4. But with a smaller APS-C sensor, such as our Canon 650D test camera, then you won’t suffer from vignetting. At 70 mm f/4, vignetting can become visible if you edit a picture significantly to increase the contrast. Think about pictures made in light fog that you want to give some more “pep”. For those who shoot in RAW: in the latest versions of Lightroom (4.4) or Photoshop (Camera Raw 4.6), there are Canon 24-70 mm f/4 IS lens correction profiles with which vignetting is easy to correct if you want to.
Distortion
As with many zoom lenses, distortion ranges from barrel-shaped at 24 mm to pincushion-shaped at 70 mm. At the shortest focal length, the barrel distortion visible. Above 28 mm it all disappears.
Canon 24-70 mm f/4 IS @ 70mm, f/4, 100 ISO, 1/800
Bokeh Canon 24-70 mm f/4 IS
Moderately bright lenses with a relatively short focal length will on a camera with an APS-C sensor rarely show a very nice bokeh. The Canon 24-70 mm f/4 IS is no exception to this rule, as you can see in the above practice shot and we included an enlargement of 100%. These kinds of practice shots are close to the “worst case” and are chosen to illustrate what we mean. If you use the Canon 24-70 mm f/4 to make pictures with little contrast in the background, then the background blur is much more balanced.
Flare Canon 24-70 mm f/4 IS
The included lens hood offers on the Canon 650D slightly less protection from flare than on a Canon camera with a full frame sensor, because the lens hood is designed for use on a camera with a full frame sensor like the Canon 5D MK3. In our practice shots, we only found a few instances of flare in the form of a rainbow or small light spots. Move your mouse over the image on the right.
Chromatic aberration
Chromatic aberration in the design of the Canon 24-70 mm f/4 is well suppressed. If we compare the chromatic aberration of the Canon 24-70 mm f/4 IS with the Canon 24-105 mm f/4 in uncorrected RAW files, then with the 24-70 mm it’s even slightly lower. But both lenses on this part resemble the Canon 24-70 mm f/2.8. However, the differences are so small, that it matters little in practice. In addition, correcting lateral chromatic aberration can be done well with software, if necessary.
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Conclusion Canon 24-70 mm f/4 IS review with a Canon APS-C camera (Canon 650D)
	See our overview of tested lenses or our overview of tested lenses with a Canon mountto compare the performances of this lens with other lenses.
WYSIWYG score: This table shows the performance of this lens if you store the files in the camera as jpg, where you have all available in-camera lens corrections applied. This score gives you for this lens/test camera combination: “What you see is what you get”.	{insertgrid ID = 308}
Pros High image quality Very solidly built and sealed against dust and moisture Built-in image stabilization is better than the image stabilization of the 24-105 mm Macro mode with 1:2 image yardstick Less expensive, lighter and more compact than the Canon 24-70 2.8 II	Cons Lower image quality than the Canon 24-70 mm 2.8 II Not inexpensive, more expensive than the Canon 24-105 mm f/4 IS Smaller zoom range than the 24-105 mm
There is a lot to choose from if selecting a lens with a zoom range of 24-70 mm for a camera with an APS-C sensor. In the selection of Canon lenses alone, you have the choice of the Canon 24-105 mm f/4 IS, Canon 24-70 mm 2.8 II or the Canon EF-S 17-55 mm f/2.8 IS. The Canon 24-70 mm f/4 in terms of image quality is a twin of the Canon 24-70 mm 2.8 II, but it does provide an extra macro mode, is lighter and significantly cheaper, In comparison to the Canon 24-105 mm f/4 IS, the image quality of the Canon 24-105 mm f/4 is a tiny bit better. But it is the improved image stabilization and macro-range that the 24-70 f/4 extra interesting. The Canon 24-70 mm f/4 is probably for many amateur photographers with a Canon 650D, 700D, 7D, or 70D a less attractive option than the cheaper Canon EF-S 17-55 mm f/2.8 IS. Photographers who want to use the lens on a camera with a full frame, or professional photographers who want to use their work under extreme weather conditions, are more likely to choose the Canon 24-70 mm f/4 or the Canon 24-70 mm f/2.8 II.