Canon EOS 70D review: A fast camera, but not for pixel peepers

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CNET Editors' Rating

4 stars Excellent
  • Overall: 8.2
  • Design: 8.0
  • Features: 8.0
  • Performance: 9.0
  • Image quality: 8.0
Review Date:
Updated on:

The Good The Canon EOS 70D's new sensor delivers excellent autofocus performance and the camera itself is quite fast. Its design is reasonably streamlined and the feature set appropriately tailored to the target market as well.

The Bad The image quality doesn't overly impress for this price class, and certain aspects of the design -- notably single card slot, hard-to-control multicontroller and the Wi-Fi/movie mode conflict resolution -- are annoying.

The Bottom Line An overall excellent camera, but one that fails to capture the best-in-class prize for image quality.

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Editors' note: This is an updated version of my preproduction preview with ratings, final image samples, and performance numbers.

There's so much to like about the eagerly awaited replacement for the Canon EOS 60D, the 70D. It comes with a completely overhauled, Live View/video-optimized autofocus system that doesn't require special lenses; a more streamlined body design with an articulated touch screen; and Wi-Fi support. And with only a couple of exceptions, I like the 70D and enjoy shooting with it; it's fast and fluid. However, pixel peepers will likely be disappointed with the still photo quality, which really should be better for the money.

Image quality
The image quality didn't change noticeably between my preproduction tests and my final tests, but my opinion has. It's...fine. Not outstanding for the money, but not bad, either. However, it's simply not as good as the Nikon D7100. Yes, it's still an advance over the 60D, but not enormously -- I don't think you even gain a full stop of usability, and any advantages seem to stem from the slight increase in resolution. It's a bit better than the Rebel T5i across the entire sensitivity range, though you really have to scrutinize them. (The T5i looks better starting at ISO 1600, but that seems to be because the T5i meters a third of a stop brighter.)

I'm beginning to think Canon really pushes the contrast on its default Picture Style to increase perceived sharpness of the photos, because when you look at details closely they seem awfully soft. You lose a lot of shadow and highlight detail if you leave the Picture Style on Auto, though. The dynamic range doesn't seem especially wide, without a lot of recoverable highlight data in the raw files and shadows that are difficult to bring up without introducing noise. The new sensor does seem to have a finer noise pattern at higher ISO sensitivities than previous sensors, though.

JPEG shots look OK up to about ISO 1600; beyond that it depends upon scene content. I was occasionally able to produce sharper images at ISO 1600 by shooting raw, but not always.

Click to download
(note: these are in the Adobe RGB color space)
ISO 100

ISO 400
ISO 1600

Thankfully, the video from the production unit looked better than the preproduction unit, though it suffers from the same general softness as stills, compounded by the relatively low resolution of HD. It displays edge artifacts -- ringing, aliasing, moire, and crawling edges -- which, as is common, get worse as ISO sensitivity rises. It looks a little better than the T5i, though not obviously, and most casual users probably won't see a big difference. Low-light video has nice tonality and a reasonable dynamic range, but there's still quite a bit of color noise.

Performance
With the exception of focusing speed in dim light, the 70D delivers excellent performance. (Looking back at my preproduction report, I think I misstated that result as 0.3 second rather than 0.7 second.) It powers on, focuses, and shoots in about 0.4 second, not quite Nikon fast, but generally fast enough and better than many Canons. Time to focus, expose, and shoot in good light runs a zippy 0.2 second and in dim light a modest 0.8 second. Two sequential JPEG or raw shots also run about 0.2 second, rising to only half a second with flash enabled. In Live View mode, that rises to 1.5 seconds.

Continuous shooting operates really fast for this class, with a sufficiently deep buffer to make the speed useful. JPEG runs past 30 shots at a rate of 7.1fps; raw shooting slowed down to about 2.5fps after about 17 shots during testing, but in field testing I sustained reasonably fast 9-shot bursts of raw+JPEG with Servo AI focus. That's pretty good for a prosumer model. (Using a 95MBps SanDisk Extreme Pro SD card.)

The new Dual Pixel CMOS AF (DPA) autofocus system is a definite update over many previous Canon models, both from a performance and features perspective. Typically, a single photodiode -- the element on a sensor that collects light and converts it to an electrical signal that carries the image information -- only passes on image data. DPA splits each photodiode in two, comparing the signals from each half using a phase-detection algorithm for autofocus, in addition to using the signal from the entire photodiode for image data. In contrast, Canon's Hybrid AF system, used by the T4i, T5i, SL1, and EOS M, simply supplements its phase-detection AF with contrast AF.

Canon USA

There are a few theoretical advantages of the new architecture. First, it has the potential to be faster, mostly because it drives the lens directly to the focus position; it doesn't have to iterate to fine-tune position like contrast AF does, and it can more quickly determine focus because it's measuring off the sensor rather than having to go through a separate phase-detection sensor cycle. Second, it covers about 80 percent of the frame (like the SL1's implementation), which improves off-center focus performance. And third, the lens shouldn't need to hunt, which makes operations like rack focus smoother when shooting video.

In practice, the system delivers; working in Live View is relatively seamless. For stills, it usually locks focus quickly and accurately, regardless of which AF-area mode it's in, and Live View is fast as well -- about 0.6 second to focus and shoot in good light. It's the first dSLR I've used in which Live View is really usable for stills. In dim conditions it's not nearly as great -- 1.5 seconds to focus and shoot. While that's not optimal for stills, it's excellent for shooting video in low light where you want the focus to glide in rather than snap. It racks really well with touch focus.

The only AF accuracy problem I ran into, and it's a common problem, is that Live View tracking AF is frequently misled into locking on things that aren't faces -- you can't disable face detection for this mode -- and tends to be too easily distracted from its target. I still wish the camera had manual focus peaking in Live View, though.

The 70D picks up Zone focus from the 7D, but I really wish it had focus-point expansion instead. Zone focus -- which lets you choose a group of AF points from which the camera then automatically selects -- helps a lot with continuous shooting, where it can be tough to keep the AF area centered over the subject. However, within the zone it still does a pretty poor of automatically selecting the correct focus areas.

The LCD is really nice, with a responsive touch screen and good visibility in most conditions. And the viewfinder, while annoyingly providing only 98 percent scene coverage, is big enough and bright enough for manual focusing.

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Where to Buy

Canon EOS 70D (with 18-55mm STM lens)

Part Number: 8469B009
Pricing is currently unavailable.

Quick Specifications See All

  • Regional specs shown for US. AU specs are unavailable.

  • Digital camera type Digital AF/AE single-lens reflex camera
  • Optical Zoom 3 x
  • Optical Sensor Type CMOS
  • Sensor Resolution 20.2 Megapixel
  • Image Stabilizer Optical
  • Optical Sensor Size 15.0 x 22.5mm
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