Canon 5D Mark III Review

I have been shooting with the Canon 5D Mark III for close to three months by now. I received it around the same time when I got a hold of the Nikon D800 and it has been a very interesting journey, shooting with both of these cameras side by side. As you may already know, I have been a Nikonian for a while now and most of the camera and lens reviews I have published to date cover Nikon products. Starting from earlier this year, I decided to expand my reach to Sony, Fujifilm and Canon cameras and lenses. While I personally prefer to stay focused on my brand of choice, some of the tests I perform compare performance across brands, so I decided that it would be best for me to get familiar with other camera systems as well. So far I have been enjoying this process and my overall impression at the moment is that all camera systems out there have their own advantages and disadvantages, just like I stated in my Nikon vs Canon vs Sony article, and no one camera system is superior than another. In short, no camera is perfect. I own a lot of Nikon gear and prefer shooting with it, because I started my journey into the world of digital photography with a Nikon DSLR. Had I started with a Canon or a Sony DSLR, my site would have been either Canon or Sony-centric instead.

As I have already stated in some of my articles, I have been really enjoying the Canon 5D Mark III. I had a great experience with its predecessor, the Canon 5D Mark II, which I used a number of times before (many of my photography friends use Canon gear and I get to play with Canon gear quite a bit). So when the 5D Mark III was announced, I knew that I definitely wanted to try it out as well, but this time for an extended period of time with a few top Canon L lenses. Loaded with Canon EF 24mm f/1.4L, Canon EF 50mm f/1.2L and Canon EF 17-40mm f/4L lenses, I have been taking the camera with me everywhere – from personal trips shooting landscapes and nature, to commercial jobs.

While reading this review, you might find a number of negative remarks about the camera. As I have said earlier, no camera is perfect and the Canon 5D Mark III is not an exception. There are things I love about it and there are things that I find rather annoying as well. It does not mean that the camera is bad and it certainly does not make it inferior to its main competitor, the Nikon D800. It is a matter of personal taste and preference. At the end of the day, it is not all about the image sensor, ISO performance or camera speed – one should assess a system as a “package”. A lot of what I say about the 5D Mark III is obviously from the standpoint of a long time Nikon shooter, so you will find plenty of comparisons and references to Nikon in this review.

1) Canon 5D Mark III Specifications

Main Features and Specifications:

1. Sensor: 22.3 MP full frame CMOS sensor, 6.25µ pixel size
2. Sensor Size: 36 x 24mm
3. Resolution: 5760 x 3840
4. Native ISO Sensitivity: 100-25,600
5. Boost Low ISO Sensitivity: 50
6. Boost High ISO Sensitivity: 51,200-102,400
7. Sensor Cleaning System: Yes
8. Image Processor: DIGIC 5+
9. Autofocus System: 61-point high-density reticular AF (up to 41 cross-type points)
10. Lens mount: Canon EF
11. Weather Sealing/Protection: Yes
12. Body Build: Full Magnesium Alloy
13. Shutter: Up to 1/8000 and 30 sec exposure
14. Storage: 1x CF and 1x SD (SD/SDHC/SDXC compatible)
15. Viewfinder Type: Pentaprism with 100% coverage, 0.71x magnification
16. Speed: 6 FPS
17. Exposure Meter: 63 Zone iFCL Metering System
18. Exposure Compensation: ±5 EV (at 1/3 EV, 1/2 EV steps)
19. Built-in Flash: No
20. LCD Screen: 3.2 inch diagonal with 1,040,000 dots
21. Movie Modes: 1920 x 1080 (29.97, 25, 23.976 fps), 1280 x 720 (59.94, 50 fps), 640 x 480 (25, 30 fps)
22. Movie Exposure Control: Full
23. Movie Recording Limit: 30 minutes
24. Movie Output: MOV (H.264)
25. Built-in Microphone: Mono
26. In-Camera HDR Capability: Yes
27. GPS: Not built-in, requires GP-E2 GPS unit
28. Battery Type: LP-E6
29. Battery Life: 950 (CIPA)
30. USB Standard: 2.0
31. Weight: 860g (excluding battery)
32. Price: $3,499 MSRP body only

A detailed list of camera specifications is available at Canon.com.

2) Canon 5D Mark III vs Canon 5D Mark II

What kind of changes does the Canon 5D Mark III bring to the table when compared to its predecessor, the Canon 5D Mark II? While detailed camera specification comparisons have already been provided in a separate Canon 5D Mark III vs 5D Mark II article, below is a short summary of changes and updates.

1. Sensor Resolution: 22.3 Million (5D Mark III) vs 21.1 Million (5D Mark II)
2. Native ISO Sensitivity: ISO 100-25,600 vs ISO 100-6,400
3. Image Processor: DIGIC 5+ vs DIGIC 4
4. Autofocus System: 61-point high-density reticular AF (up to 41 cross-type points) vs 9-point TTL (1 cross-type point)
5. Viewfinder Coverage: 100% vs 98%
6. Storage Media: 1xCF and 1xSD vs 1xCF
7. Speed: 6 fps vs 3.9 fps
8. Exposure Metering Sensor: iFCL metering with 63 zone dual-layer sensor vs TTL full aperture metering 35 zone SPC
9. LCD Size: 3.2″ LCD vs 3.0″ LCD
10. LCD Resolution: 1,040,000 dots vs 920,000 dots
11. HDR Support: Yes vs No
12. Chromatic Aberration Correction: Yes vs No
13. Silent shutter: Yes vs No

The above are the most significant differences – there are some other minor differences as well.

First, let’s talk about the camera sensor. While 22.3 MP vs 21.1 MP change might seem rather insignificant (nothing like the 24 MP jump from D700 to D800), the sensor on the 5D Mark III has gone through some interesting changes. Its ISO range has been expanded from 6,400 to 25,600 – two more full stops, as seen in product sheets and claimed by Canon. In reality, the situation is a little bit different, but I won’t disclose my findings quite yet, you will see my test results in the camera comparisons page of this review.

The autofocus system on the 5D series cameras has been a source of complaints for a while now. When the Canon 5D Mark II was released, photographers were disappointed by the fact that Canon was still bundling its old 9 point AF system with only one cross-type sensor, while Nikon was shipping its advanced 51 point AF system on even its cropped-sensor cameras like Nikon D300s. This time around, after hearing so many complaints from its customers, Canon finally decided to change the AF system on the 5D line. And the new AF system is not a joke – it is the same one that Canon is using on its top-of-the-line Canon EOS 1D X camera.

Framing images has gotten better, since the viewfinder finally offers 100% coverage. The LCD screen on the back of the camera has also gotten bigger with more dots to show more details. The DIGIC image processor gained some more power, which helped increase the speed of the camera from 3.9 fps to 6 fps (as a comparison, the Nikon D800 is limited to 4 fps). Faster speed means that the Canon 5D Mark III is now worth looking into as an option for sports and wildlife photography as well. A faster DIGIC 5+ processor also means that the Canon 5D Mark III can do some complex image processing – the camera can shoot in HDR and has built-in chromatic aberration correction, neither of which were possible on the 5D Mark II. Finally, the silent shutter of the 5D Mark III is a very useful feature when shooting in noise-sensitive environments.

As you can see, there is quite a difference between the two cameras. The AF system alone is a huge change.

3) Canon 5D Mark III vs Nikon D800

When it comes to comparing the two cameras, one has to be very careful in assessing sensor performance. Since there is such a huge difference in sensor resolution, looking at images at 100% view (pixel level) will obviously give advantage to the Canon 5D Mark III, simply because the latter has bigger pixels and hence its per pixel noise characteristics are going to be better. The proper comparison method, however, involves a down-sampling process, in which a higher-resolution image is resized to a smaller resolution. So in this case, the only proper way to compare the two cameras, is to take a 36.3 MP image from the Nikon D800 and decrease it to Canon 5D Mark III’s 22.3 MP resolution. This can be easily done in post-processing software like Photoshop and Lightroom and the comparison of the two, along with my personal analysis are presented in my Nikon D800 Review. In short, once down-sampled, the Nikon D800 yields exceptionally good images at high ISO levels and actually looks slightly better than the 5D Mark III at ISO 3200 and above. Lastly, the dynamic range of the Nikon D800 is phenomenal. According to DxOMark, the Nikon D800 has better dynamic range than all medium format cameras they have tested so far. The same cannot be said about the Canon 5D Mark III – its dynamic range is certainly inferior (see the “Dynamic Range” section of the review for more details). Let’s take a look at other differences in camera specifications – a full comparison is provided in my Canon 5D Mark III vs Nikon D800 article that I posted earlier.

1. Sensor Resolution: 22.3 MP (Canon 5D Mark III) vs 36.3 MP (Nikon D800)
2. Native ISO Sensitivity: ISO 100-25,600 vs ISO 100-6,400
3. Boosted ISO Sensitivity: ISO 51,200-102,400 vs ISO 12,800-25,600
4. Image Size: 5760 x 3840 vs 7360 x 4912
5. Continuous Shooting Speed: 6 fps vs 4 fps
6. Shutter Durability: 150,000 cycles vs 200,000 cycles
7. Autofocus System: 61-point AF (up to 41 cross-type points) vs 51-point AF (up to 15 cross-type points)
8. AF Detection: f/5.6 vs f/8
9. Built-in Flash: No vs Yes
10. AF Assist: No vs Yes
11. Uncompressed Video Output: No vs Yes
12. LCD Resolution: 1,040,000 dots vs 921,000 dots
13. Battery Life: 950 shots (CIPA) vs 850 shots (CIPA)
14. USB Version: 2.0 vs 3.0
15. Weight: 860g vs 900g
16. MSRP Price: $3,499 vs $2,999

Aside from the above-mentioned differences in sensor resolution and ISO performance, the Canon 5D Mark III has faster shooting speed, more AF focus points with more cross-type sensors (more on the AF system of the 5D Mark III further below), better LCD screen, better battery life and lighter body. On the flip side, its shutter durability is rated at 150K versus 200K on the D800, it has no built-in flash or AF assist for focusing in low-light environments, it has no uncompressed HDMI video output (only relevant to videographers) and it is $500 USD more expensive than the D800. In addition, the Nikon D800 can autofocus with lenses up to f/8, which means that if you have a slower f/4 lens, autofocus is still operational when a 2x teleconverter is used (certainly an advantage for wildlife photographers). Again, both have their pros and cons, so you have to weigh in which features are more important for your photography needs.

4) Camera construction and handling

Just like the older Canon 5D Mark II and the Nikon D800, the Canon 5D Mark III has a weather-sealed magnesium-alloy body, making it a very tough camera to use in pretty much any environment. As some people like to say, it surely is built like a tank. The camera feels very solid in hands and judging from its construction and build, it will last a very long time. I have taken the 5D Mark III with me to extremely humid temperatures (rainy May in Florida) and very cold weather (below freezing temperatures in Colorado mountains) and it performed flawlessly. High winds in a dusty area were also not a problem, although I would recommend to be careful in such environments, since dust can make its way into the camera through a lens (which is quite normal and applicable to all DSLR cameras).

Handling-wise, I find the Canon 5D Mark III to be superb. In fact, I actually prefer it to the D800, primarily because of its more extruded and very comfortable grip. The controls of the camera very much resemble the Canon 7D and I also find them to be designed very well – much better than on the 5D Mark II for sure. The camera is extremely customizable and many buttons on the camera can be set to perform different functions, which is expected from this class of a camera. The toughest thing to get used to was the lack of a rear dial. I am very used to the dual dial setup on Nikon DSLRs (with one on the front and one on the back), which makes it easy to change aperture and shutter speed in different camera modes. On the Canon 5D Mark III, the top rotary dial changes its behavior depending on what mode you are in. For example, in aperture priority mode, the dial changes the lens aperture; in shutter priority and manual modes, it changes the camera shutter speed. The big rotary dial on the back of the camera is used for exposure compensation in aperture and shutter priority modes and switches to changing aperture in manual mode. It took some time to get used to this behavior, and to be honest, I still prefer the Nikon way.

The left back side of the camera has a similar layout as the D800, except some of the buttons serve different purposes. I like the button placement, except for the “Rate” button. The good news is that if you choose to rate your photographs in your camera, the information is carried over to Lightroom and Aperture when the images are imported. On the other hand, why would you want to rate pictures on your camera looking at the tiny LCD screen in first place? I sort through and rate my photographs in Lightroom and if there is something wrong with a picture I took, I simply delete it. When working in the field, I do not have the time to sit and look through images on the camera – I import them into my computer as soon as possible. And I know that I am not the only photographer that has such a workflow. I really wish the Rate button was swapped with another zoom button, just like on the D800. One button would be used for zooming in and another for zooming out. I prefer using two buttons to zoom in/out instead of pressing a button, then changing zoom levels with a rotary dial on the top of the camera. Nikon moved away from this bad ergonomic design on its pro cameras and Canon should have done the same.

The viewfinder on the 5D Mark III is recessed very deep inside, making it almost impossible to clean it quickly. When the viewfinder fogged up, I had a hard time reaching the glass surface to wipe it. The Nikon D800, on the other hand does not have this problem and its viewfinder eyepiece is very easy to reach and clean. Another design annoyance is the way the viewfinder is blocked. On the Nikon D800, there is a small switch on the top left side of the viewfinder that allows you to block the viewfinder when shooting at night. On the Canon 5D Mark III, you have to take off the eye piece, then use a plastic piece on the camera strap to block the light. This is inconvenient and downright idiotic, in my opinion. I would rather use a tape to block the viewfinder than do what Canon wants me to do.

The LCD screen on the 5D Mark III is gorgeous. Canon used hardened glass protector in front of the LCD with anti-reflective coating, which makes it very practical to use in the field. The screen looks a little darker, but playing back images in an outdoor environment is a much better experience on the 5D Mark III than on the D800. You can see all the colors and you don’t have to use your hands to block sunlight, which is very nice. The Nikon D800 has no anti-reflective coating and both the LCD and the screen protector reflect like crazy.

After being used to Nikon’s multi-function button, getting used to a rotary dial with a separate joystick took me some time to get used to. I just have this thing against joysticks and I find them uncomfortable to use (yes, I dislike the two joysticks on the Nikon D4 as well and I wish Nikon did not steal the joystick idea from Canon). Plus, my thumb gets sore when I use a joystick for an extended period of time. Aside from the joystick, once I got used to the Canon layout, operating the camera was pretty easy.

Lastly, one thing drove me nuts for a while, until I found a way to fix it. By default, the joystick on the back of the camera is programmed to do nothing when looking through the viewfinder, so it cannot be used for moving AF points. On Nikon DSLRs, the AF focus point is moved by the multi-function joystick. I just could not believe that I constantly had to press the AF selector button in order to change my focus point, so with the help of my friend Sergey (who is a long time Canon shooter), I was able to find a way to take care of this problem. Here are the instructions on how we did it: Press the “Info” button, then the “Q” button, then navigate to “Custom Controls” with the joystick, scroll down to the very last option “Multi-controller AF point direct selection” and set it to “AF point direct selection” instead of the default “OFF”. Once you do this, you will be able to change the AF focus point with the joystick.

Overall, I find the Canon 5D Mark III to be superior to the Nikon D800 in terms of handling, but I still prefer Nikon’s ergonomics.

5) Camera Sensor

Without a doubt, the most important feature of a digital camera today is its image sensor. You could put the most advanced autofocus and metering systems with a boatload of great features into a camera, but at the end of the day, they are all more or less secondary – the sensor performance is still looked at first. Things like resolution, dynamic range, diffraction, color depth and ISO performance are all tightly related to the sensor and its physical size.

Canon claims the 5D Mark III to have a much better sensor with a two stop improvement over the Canon 5D Mark II – its “native” ISO range has been expanded from ISO 6,400 to 25,600. Sounds like a huge difference, which should make images from the Canon 5D Mark III look much better in comparison, especially when high ISO images are down-sampled to a smaller resolution (see my “how to resize images in Lightroom” and “how to resize images in Photoshop” for an in-depth explanation of the down-sampling process).

The sensor went through some physical changes. Its physical dimensions stayed the same, but the resolution increased by over a megapixel – from 21.1 MP to 22.3 MP. So technically, this means more resolution while delivering better low-light performance. Does the new sensor deliver? How does it truly compare to the previous generation Canon 5D Mark II? See the “Camera Comparisons” page for more details.

6) Dynamic Range

Measuring dynamic range of a camera is a complex process that requires a good, consistent methodology, especially when doing cross-brand comparisons. Since I have been shooting with both the Canon 5D Mark III and the Nikon D800 side by side, I can say that the D800 clearly has the lead in dynamic range. This difference was obvious when I shot the same scene with both cameras, at very similar camera settings. The Canon 5D Mark III consistently overexposed highlights, while the D800 rarely did (the exposure was similar on both). The dynamic range difference was even more obvious when post-processing images in Lightroom – I clearly had more options for recovering data on D800 images than I did with the 5D Mark III.

Because I do not have a way to actually measure dynamic range in numbers, I rely on DxOMark for sensor rankings – I find their results to be on par with what I can get when recovering images in Lightroom and Photoshop. Unfortunately, the Canon 5D Mark III does not seem to perform well according to DxOMark. They rated the Canon 5D Mark III 51st among all cameras, which puts it below many Nikon, Sony and Pentax cameras and sadly, below even many APS-C size sensors. Even the older Canon 5D Mark II yields better dynamic range in comparison. Here is a screenshot from the Dynamic Range tab from DxOMark’s Camera Sensor Ratings page:

Some people take DxOMark measurements with a grain of salt and I agree – you cannot always trust one source for these types of measurements. In fact, the same applies to my reviews as well – my experience with a particular piece of equipment might differ substantially from another reviewer. However, after looking at many different images from both cameras, I do agree with DxOMark’s assessment. For example, take a look at the below two image crops from the 5D Mark III and D800:

The original images (RAW) were exposed the same on both cameras, both at base ISO of 100. After I imported them into Lightroom, I moved the “Shadows” slider all the way to 100 and then picked the darkest part of the image for the above crop. As you can see, the Canon 5D Mark III crop looks much noisier in comparison and retains less colors and details compared to the Nikon D800 crop. When pulling details from shadows, the Nikon D800 has a lot more information to work with.

7) Autofocus Performance

As I have already pointed out earlier, Canon finally integrated its best autofocus system into the 5D Mark III. Instead of the old 9 focus point system with a single cross-type sensor that was used on both the original 5D and the 5D Mark II, Canon decided to use the same professional AF system it uses on its flagship Canon 1D X DSLR. This was a very welcome move, because if Canon continued with its old AF system, it would have severely threatened the 5D line, making the 5D Mark III a worthless upgrade. The new 61 point AF system is the most advanced AF system Canon developed thus far, making autofocus the most appealing feature of the camera. With a whopping 41 cross-type sensors, Canon is pretty serious about fixing its damaged reputation (the whole fiasco with the previous AF systems on 1D line cost the company many sports and wildlife photographers). In comparison, the Nikon D800 and D4 DSLRs have 51 AF points with 15 cross-type sensors.

But all these numbers can be just numbers if the AF system is not reliable. I have been shooting with Nikon pro bodies since the original D3 and I find the Multi-CAM 3500FX system to be very reliable. The new Advanced Multi-CAM 3500FX that is featured on the D800 and D4 is even better, because it can autofocus with f/8 lenses. Having been spoiled with an excellent AF system, my goal was to assess Canon’s 61 point AF system and see how it fares in comparison, especially when shooting in low light situations. As I shot with the Canon 5D Mark III, I took notes of my observations in different situations.

The center focus point of the Canon 5D Mark III is very fast and accurate, even in low-light situations. For most of my testing, I used two primes – the Canon 50mm f/1.2L and the Canon 24mm f/1.4L, as well as two zoom lenses – the Canon 17-40mm f/4L and the Canon 70-200mm f/4L IS. All four performed very well in the center focus point area and I had a lot of keepers, I would say about the same as I get with the Nikon AF system. In fact, most focus points around the center area (total of 27) were dead on most of the time, which is very good news. Another plus of the new Canon AF system is its reach – the 61 AF points cover a bigger viewfinder area than Nikon’s AF system and more focus points give you the flexibility to pick a precise point to focus on while composing.

If you are used to the old Canon 5D & 5D Mark II mentality of always using the center focus point and constantly recomposing your shots, you don’t have to do the same with this camera – just pick the AF point you want to use and as long as there is enough texture and contrast on your subject, you should not have to worry about out of focus subjects. As I have explained in my DSLR Autofocus Modes article, you have to be careful when focusing with one focus point and recomposing, because the focus plane changes. While this might not be noticeable with wide angle lenses at small apertures, it surely can result in blurry images with longer lenses at large apertures. With the new AF system, you have so many focus points, that you do not have to play the old focus and recompose game.

The left and right cross type sensors also work pretty well, but they are not as accurate as the ones in the center. Other focus points located at the very far left and right can be tricky to deal with and I try to avoid them, since they clearly lack the precision of the cross-type sensors. I ended up turning off these focus points, as they seemed to work rather poorly with slower lenses and the Canon 50mm f/1.2L (which can be tricky to work with).

There are so many customization options for the autofocus system, that it took me some time to understand how the AF system functions. The Canon language for AF functions is totally different from Nikon’s, which made it tougher for me to get a quick grasp of the system. I would encourage to experiment with the AF system using the camera manual – there is a lot to cover. The really nice feature of the AF system on the Canon 5D Mark III are the provided presets on the first page of the AF setup menu. Instead of manually tweaking AF settings (which can be quite painful to understand), Canon provided 6 user presets for different shooting scenarios:

Now this is a really neat idea that I hope Canon will use in all of its cameras going forward. It is so much easier to pick a preset based on your needs, rather than having to fiddle with all the AF settings and the not-so-easy-to-understand technical language.

Overall, I am quite impressed by Canon’s new 61-point AF system. Canon did the right thing by including it in the 5D Mark III. The AF system alone, in my opinion, is worth the upgrade from 5D Mark II. Finally, the Canon 5D Mark III is becoming an appealing camera for sports and wildlife photographers, thanks to its fast autofocus and 6 fps speed (more on the burst speed and buffer size in section 9 of this review).

8) Metering and Exposure

Unlike Nikon, which includes the same metering system on its flagship products as on the lower-end FX line (D700, D800), Canon decided to borrow the 63 zone metering sensor from the 3 year old 7D, instead of the new 100,000 pixel RGB sensor that is used on the flagship Canon 1D X. While this is an improvement over the old 35 zone sensor used on the 5D Mark III, it is still a little disappointing that we are getting a great AF system that is linked with an older metering sensor. This essentially means that the Canon 5D Mark III could perform worse than the Canon 1D X when tracking subjects as well. In comparison, the Nikon D800 has the same 91,000-pixel RGB metering sensor that is used on the flagship Nikon D4, so both AF and metering systems are identical.

An inferior metering system was not a problem during the launch of the Canon 5D Mark III though. As I previously reported, the Canon 5D Mark III had a rather serious light leak issue on its top LCD panel that affected camera metering. Once Canon confirmed that all Canon 5D Mark III cameras had this problem, it offered a free service to existing camera owners and started patching up all newly released cameras as well. Canon’s solution was to simply use a black tape inside the camera to prevent the light leak, which later became a heated debate among some of the 5D Mark III owners, who were concerned about the black tape potentially breaking up in pieces over time and causing problems. I trust that Canon used a high quality tape that will not react to extreme weather temperatures, but only time will tell if it ever becomes a problem. It is quite normal for a newly released camera to have issues at its launch. Most manufacturers, including Nikon, have had problems with their new camera models in the past as well. Most issues, however, have to do with buggy camera firmware, which can be patched up later via firmware updates. Design issues are a lot more serious and they can potentially result in product recalls and service orders that can seriously hurt company’s financials and its image.

So how reliable and accurate is the 63 zone metering sensor on the 5D Mark III? I found it to be fairly accurate in most situations. Interestingly, I did not experience any overexposure issues as the 7D, which means that Canon might have slightly tweaked the metering system on the 5D Mark III. All metering modes (evaluative, center weighted, partial and spot metering) worked as expected and when I did have exposure problems in some rare situations, taking care of the exposure issues with the 5-step exposure compensation using the big rotary dial on the back of the camera was easy. I have not played with the Canon 1D X yet to see how much more improved the metering system is, but I am sure it will not disappoint.

9) Shooting Speed (FPS) and Battery Life

One of the key differences between the Canon 5D Mark III and the Nikon D800, is its shooting speed of 6 frames per second (fps) versus 4 frames per second on the D800. Granted, the Canon 5D Mark III has a lot less pixels to process in comparison (with smaller RAW/JPEG files to write), which is why it is a faster camera. While 2 frames per second might not sound like much, the speed difference is quite noticeable when shooting fast-action photography. The Nikon D800 can speed up to 6 fps with a battery grip, but only when shooting at less than half the resolution (in DX mode at 15.3 MP). And in DX mode not only does it have less resolution, but its pixel-level performance is also going to be inferior, since there is no down-sampling advantage anymore. The camera buffer, on the other hand, could have been a little bigger on the 5D Mark III to make it more attractive for fast action. My measurements for buffer capacity are roughly 16-17 RAW files until it gets full (using a 16 GB SanDisk Extreme Pro 90 MB/sec CF memory), which is about the same as what the Nikon D800 has. Since the D800 files are bigger in size, it essentially means that the buffer size of the 5D Mark III is smaller and the camera will slow down in less time (~2.7 seconds on the 5D Mark III versus ~4 seconds on the D800).

The Canon 5D Mark III uses the same battery as the Canon 5D Mark II, which is rated at 950 shots. I found no problems with battery usage and the battery indicator seems to be pretty accurate. My first run was about 900 shots total and that’s considering that I zoomed in and viewed a lot of the first images. If I turned off image review, I am sure that I could have easily squeezed well over a thousand images.

10) Live View

Canon’s implementation of Live View is excellent. I love the way Canon designed the Live View/Movie switch with the Start/Stop button that changes in functionality depending on whether you are in movie or live view mode. Changing the switch to video mode automatically flips the mirror up and starts the video mode and the Star/Stop button is used for recording video. If you prefer the shutter release button to start and stop video, you can do this from the camera menu. Once you switch to movie mode, if you access the camera menu, you will see a new option called “Shoot 5: Movie”. Within that menu simply go to the “Movie shoot. btn” setting and change it from “Start Stop” to the shutter release button image / Start Stop.

The Canon 5D Mark III has a better image magnification implementation than the D800. You have two zoom levels to zoom in to (using the Zoom button on the left of the camera) – 5x and 10x. Both are done on the pixel level, which makes this feature very useful for precise focusing. I used this feature quite a bit when testing Canon lenses and I find these two zoom levels to be sufficient. The D800, on the other hand, has five different zoom levels, but they are not on pixel level (1:1), meaning the magnification levels are interpolated. The Nikon D90 suffered from this problem, making it tough to obtain critical focus and test lenses, and looks like the D800 is designed to be the same way. I am not sure why Nikon decided to do this, because all other pro DSLRs have a 1:1 magnification level, including the Nikon D700.

11) Chromatic Aberration Correction

The Canon 5D Mark III is the first Canon full-frame DSLR that has Chromatic Aberration Correction feature built into the camera firmware (vignetting and distortion correction have been available previously). Unlike Nikon DSLRs that perform automatic chromatic aberration correction with an algorithm that works with any Nikon lens, Canon decided to program correction for specific Canon EF lenses. While this method might be more accurate, it has one major drawback – the lens database stored on the camera needs to be updated when a new lens becomes available.

Now keep in mind that both Nikon and Canon apply lens corrections on JPEG images. When writing RAW files, both store their proprietary lens correction data differently and these corrections can only be read with manufacturer software like Capture NX (Nikon) and DPP (Canon). If you import RAW images into Lightroom, none of the applied lens corrections will be visible, so you will have to use Lightroom’s “Lens Correction” module instead.

12) Movie Mode

Despite the fact that Nikon was the first in the world to introduce video recording capability on its Nikon D90 DSLR, the Canon 5D Mark II was the one that truly shook the world, because it featured impressive 1080p video capabilities, making it a huge success among videographers and later becoming a serious video recording alternative for Hollywood movie production. The Canon 5D Mark II was a pioneer that heavily influenced the video recording industry and started some new trends like wedding videography with a DSLR.

Many 5D Mark II owners eagerly awaited the successor, hoping to get even more video capabilities such as 4K video, 1080p with 60+ fps, reduction of moiré, addressing of the rolling-shutter effect issue, headphone socket and a few other “nice to have” features. To their surprise, Canon only partially addressed some of the requests and none of the groundbreaking capabilities made it to the Canon 5D Mark III. And when someone like Vincent Laforet, who pretty much made the Canon 5D Mark II popular for videography did not feel very excited about the video capabilities of the 5D Mark III, you know that Canon could have done better.

Now this does not make the 5D Mark III a bad camera for recording movies. It is noticeably better than the 5D Mark II, especially in low-light video performance, which still makes the 5D Mark III one of the best interchangeable lens video cameras on the market under $4K. I am sure it will continue to be used as the camera of choice for other production videos. Canon later announced some advanced video cameras like the Canon EOS 1D C and Canon EOS C300, so it became clear to me afterwards that it simply did not want the 5D Mark III to compete against dedicated and expensive video cameras. Canon knows that there is a good market for high-end video cameras, so it decided to focus on a completely different product line for video instead. I very much doubt that we will see 4K video in the Canon 5D Mark IV – we will probably just get better picture quality, color reproduction, dynamic range and faster than 30 fps 1080p mode. Unless someone else pioneers 4K to become a standard video feature in digital cameras.

See the next page to see more examples of Canon 5D Mark III’s ISO performance, along with comparisons to Canon 5D Mark II, Nikon D3s and Nikon D800.

13) ISO Performance at low ISOs (ISO 100-800)

Some technical junk:

1. White Balance: Auto, changed to Custom, Temp: 4500, Tint: +22
2. EXIF information is preserved in the images
3. Focusing was performed through Live-View Contrast Detect
4. Long exposure NR: Off
5. High ISO NR: Off
6. Image Format: RAW
7. Imported images into Lightroom 4 and normalized to 12 MP resolution
8. Lightroom export: sRGB JPEG Quality 80

Here is the full image, showing which area of the image I cropped below:

Let’s take a look at how the Canon 5D Mark III performs at low ISOs. Here are some crops at ISO 100, 200, 400 and 800:

As expected, the Canon 5D Mark III produces beautifully rendered images at low ISO levels. The noise is practically non-existent, even at ISO 800.

14) High ISO Performance (ISO 1600-25600)

High ISO performance is a very important measure of DSLR sensor quality for low-light photography. Here is how the Canon 5D Mark III performs at high ISO levels between ISO 1600 and 6400:

As we increase ISO to 1600, a little bit of grain starts showing up in images. ISO 3200 adds noticeable grain throughout the image, but colors and details are well preserved.

Jumping to ISO 6400 adds significantly more noise, which is especially visible in the shadows. ISO 12800 is much worse than ISO 6400, which is now affecting shadow details and colors.

The maximum native ISO sensitivity of 25600 is clearly the limit – the amount of noise doubles and now we are seeing plenty of large grain throughout the image. There is a noticeable amount of detail and color loss here.

15) High ISO Performance “Boost” (ISO 51200-102400)

Canon 5D Mark III has two extra ISO “boost” levels – ISO 51200 and ISO 102400 for extreme situations. Take a look at these:

ISO 51200 is pretty useless, unless you heavily down-sample the image, whereas ISO 102400 is downright unacceptable for my taste, even for down-sampling purposes.

16) ISO Performance Summary

The Canon 5D Mark III produces excellent results at low ISOs. As you can see from the above, images are very clean from ISO 100 to 800 and it pretty much stays that way all the way to ISO 1600. Beyond ISO 1600 we start seeing noticeable noise that first starts affecting the shadow colors and details, then progressively gets worse at each ISO stop. Image quality quickly deteriorates starting from ISO 6400 and ISO 25600 is pretty much the limit of acceptable image quality. The boosted ISO levels 51200 and 102400 are useless in my opinion – they lack too much detail and colors bleed all over the image.

Overall, given the high-resolution 22.3 MP sensor, the Canon 5D Mark III produces excellent results, especially when the image is down-sampled to a smaller resolution.

It is hard to judge the performance of the Canon 5D Mark III without direct comparison against other professional cameras, which is why you should definitely check out the comparisons on the next page as well.

Compared to Canon 5D Mark II

Let’s see how much better the new 5D Mark III is compared to the older 5D Mark II.

17) Canon 5D Mark III vs Canon 5D Mark II ISO Comparison at Low ISOs

Here are some low ISO image comparisons between ISO 100 and 800 (Left: Canon 5D Mark III, Right: Canon 5D Mark II):

It is hard to see much difference between the two cameras at low ISO levels – both perform really well from ISO 100 to 400.

At ISO 800, the Canon 5D Mark II seems to have a little more noticeable noise, but it is still quite good in comparison.

18) Canon 5D Mark III vs Canon 5D Mark II High ISO Comparison

The situation starts to change when ISO levels are increased on both cameras:

You can see a little more noise on the 5D Mark II throughout the image, especially in the shadows.

ISO 3200 still looks worse on the 5D Mark II.

And ISO 6400 is noticeably worse on the 5D Mark II, especially in the shadow areas – noise is more pronounced and grain is clearly bigger in size. I did not bother providing boosted ISO levels on the 5D Mark II, because they look very similar to the above ISO 6400 crop, with the 5D Mark II having more noise with higher color and detail loss.

19) Canon 5D Mark III vs Canon 5D Mark II Summary

At low ISO levels from 100 to 400, both DSLRs look very similar with no noticeable noise. At about ISO 800 though, the Canon 5D Mark III takes the lead, providing cleaner images with more details and colors. The difference in sensors is clearly seen at ISO 6400, where the 5D Mark II seems to be about 2/3 of a stop worse in comparison. The biggest advantage of the new 5D Mark III sensor seems to be at high ISO levels, where it seems to apply a more clever noise reduction algorithm, similar to what Nikon did when going from D3 to D3s. Also, the resolution of the 5D Mark III is a little higher in comparison, so the size of pixels got a little smaller, while noise performance has gotten better. Had the number of pixels stayed the same, we would have seen even better performance, but Canon probably did not want to look like it did nothing to the physical sensor. Is there are a two stop difference between the Canon 5D Mark III and 5D Mark II like Canon has been claiming? No, absolutely not. Simply because the new 5D Mark III has two more native ISO levels to use does not mean that it is in fact two stops better. See the above crops for yourself – do you see a two stop difference at any ISO level? If there was a two stop difference, ISO 6400 on the 5D Mark III would have looked about the same as ISO 1600 on the 5D Mark II – it clearly does not. Sadly, the 2 stop improvement claim is just a myth – it is a clever marketing trick that all manufacturers are sadly using today to make people believe that an upgrade is justified. The 3 year old sensor on the 5D Mark II still yields beautiful images that are only marginally worse, and only at high ISOs.

Please note that all of the above images were compared in RAW format, processed by Adobe Photoshop Lightroom.

Compared to Nikon D3s

What about comparing the Canon 5D Mark III to the Nikon D3s? Let’s take a look.

20) Canon 5D Mark III vs D3s ISO Comparison at low ISOs

Similarly to the 5D Mark II, I cannot see much difference between the two cameras at low ISO levels – both perform really well from ISO 100 to 400.

Stopped down to ISO 800, the Nikon D3s looks a tad cleaner in comparison.

21) Canon 5D Mark III vs D3s High ISO Comparison

Let’s see what happens when both are pushed to ISO 1600 and above:

ISO 1600 also looks very comparable between the two cameras, although the Nikon D3s looks a little cleaner to me. While both were shot at the same exposure, the Canon 5D Mark III image is still a little brighter, which contributes to more noise in the shadows. I tried dialing 1/3 negative exposure in Lightroom, but the D3s image still looked cleaner overall.

At ISO 3200, the Canon 5D Mark III shows more pronounced noise in the shadows.

And as you can see from the image itself, the difference is even more obvious at ISO 6400.

Increasing ISO to 12800 again results in better performance by the D3s, with about 2/3 of a stop difference.

When pushed to ISO 25,600, the Nikon D3s is cleaner and retains colors, while the Canon 5D Mark III is much noisier in comparison. The process of down-sampling the image from 22.3 MP to 12 MP does help the Canon 5D Mark III quite a bit in terms of details, but there is still way more noise throughout the image.

22) Canon 5D Mark III vs D3s Summary

The Nikon D3s has been Nikon’s best low-light camera since it came out in 2009. When the Nikon D4 came out, I thought it would be about a full stop better than the D3s that it replaced. As it turned out and I reported in my Nikon D4 vs D3s ISO Performance Comparison article, the Nikon D4 pretty much matched the performance of the D3s when images were down-sampled to the same resolution – there was not a full stop of difference between the two. So Nikon pretty much kept the high ISO performance the same, but provided more options for resolution at lower ISO levels. Hence, I saw no reason to try to compare the Canon 5D Mark III to the D4 (which I am still waiting for) and I used my D3s for a comparison instead.

As it turned out, when properly down-sampled, the Canon 5D Mark III performs quite well at lower ISO levels and only struggles at very high ISOs, where it is up to 1 stop inferior in performance.

Compared to Nikon D800

Let’s see how the Canon 5D Mark III compares to the Nikon D800.

23) Canon 5D Mark III vs Nikon D800 ISO Comparison at Low ISOs

At base ISO, both are very clean, with very similar output and detail.

Unlike the 5D Mark II, the new 5D Mark III matches the performance of the D800 at ISO 800.

24) Canon 5D Mark III vs Nikon D800 High ISO Comparison

Let’s see what happens at high ISO levels above ISO 1600:

Looks like the D800 is a tad cleaner in the shadows, otherwise both show very good performance.

ISO 3200 is clearly noisier on the Canon 5D Mark III, as can be seen from the above image and the grain is a bit larger too (again, mostly due to down-sampling).

And even more so at ISO 6400 – look at the shadows.

The grain throughout the frame is bigger on the 5D Mark III at ISO 12,800, although there is not a huge difference. I would say between 1/3 to 2/3 of a stop max.

Pushed to ISO 25,600, both are pretty similar, although the Canon 5D Mark III still shows larger noise artifacts. Again, down-sampling does the magic for the D800 here!

25) Canon 5D Mark III vs Nikon D800 Summary

As you can see, the Nikon D800 sensor performs overall better than the sensor on the Canon 5D Mark III. Although the Canon 5D Mark III shows impressive levels of noise at lower ISO levels, it still cannot quite match what the D800 can do when images are normalized to the same print size. Don’t forget that there is also a big resolution difference between the two – the Nikon D800 is 36.3 MP, while the Canon 5D Mark III is 22.3 MP. So at base ISO levels, the Nikon D800 is going to have a resolution advantage for landscape and fashion work. And as I have already shown in the first page of this review, the Nikon D800 also has much more dynamic range in comparison.

26) Summary

When Canon introduced the highly anticipated 5D Mark III to the market, the photography community and many Canon fans felt underwhelmed by its specifications, especially after the big shock wave left by the Nikon D800. For the first time, it felt like Canon and Nikon reversed their game – instead of focusing on more megapixels like it has been doing for many years now, Canon decided to keep the resolution of the camera about the same at 22.3 MP (versus 21.1 MP on the 5D Mark II) and concentrate on other important features such as low-light performance, camera build, ergonomics, AF system, ease of use and speed. It seemed like Canon finally listened to its customers and designed a much better overall camera, so how did the 5D Mark III manage to disappoint so many photographers? A big part of the reason was high expectations for sensor performance. The world wanted a much better sensor from Canon, not something similar to a 3 year old model. Yes, the 5D Mark III did gain 2 more stops of native ISO sensitivity, but detailed ISO performance comparisons revealed a different picture – there is actually a maximum of one full stop of difference between the two sensors. Hence, the new 5D Mark III only got marginally improved in image quality…

However, the same cannot be said about other important camera features. As I have already pointed out, the new autofocus system alone is a huge leap forward. With a 61-focus high-density AF and up to 41 cross-type points, coupled with the 63 Zone iFCL Metering System from the Canon 7D, it is surely one of the most advanced autofocus systems we have seen to date. The previous 9 focus points and 1 cross-type point on the 5D Mark II sound like a joke in comparison. After three months of testing the camera, I find the AF system to be reliable with quick and accurate focus, even in low-light situations. Thanks to this much improved autofocus system and the new DIGIC 5+ image processor that allows processing images at 6 frames per second, the 5D Mark III has now become a very appealing option for sports and wildlife photographers. My personal favorite feature is the silent shutter on the Canon 5D Mark III. After years of using Nikon cameras, the silent shutter sound of the 5D Mark III is like music to my ears. And other updates such as 100% viewfinder coverage, dual memory card support, bigger and higher quality LCD screen and in-camera lens corrections are like icing on the cake.

Overall, I am very impressed by the Canon 5D Mark III. It is a very capable camera that can deliver outstanding results, especially with the wide selection of superb Canon L glass. If I were to invest in a Canon DSLR system today, given its capabilities and price range, the Canon 5D Mark III would without a doubt be my camera of choice. It is not a game changer like the Nikon D800, but it sure is a huge step up from the previous generation 5D Mark II, which has been the most popular full-frame camera on the market since it came out in 2009.

27) Where to buy and availability

B&H is currently selling the Canon 5D Mark III body only for $3,499.

28) More image samples

All Images Copyright © Nasim Mansurov, All Rights Reserved. Copying or reproduction is not permitted without written permission from the author.