Canon 5D Mark IV vs. 5D Mark III
Though it may look a lot like its predecessor, the new Canon 5D Mark IV has a number of technical improvements and new features underneath its familiar outer shell that make it a well-rounded and sizable upgrade over the Canon 5D Mark III from 2012.
Exterior: Familiar design but with better weather sealing & a touchscreen
As a professional tool, it makes sense that Canon took a conservative route regarding an external redesign since doing so makes it much easier for experienced 5D-series owners to pick up the new camera and get to work. There's no significant learning curve or anything to disrupt their likely well-developed muscle memory in terms of the camera's controls.
Controls are more or less identical between these two cameras, though a major upgrade for the Mark IV is the inclusion of touchscreen functionality to the rear LCD, something the 5D Mark III lacks entirely. As a camera designed for both still photography and video, the addition of a touchscreen is very handy. In live view mode, you can simply tap the screen to adjust focus, as well as silently make exposure adjustments, avoiding unwanted noises from getting picked up by the microphone during video recording. The 5D Mark IV's menus are also fully touch-enabled for those who want to navigate them that way, though it's not entirely necessary.
Lastly, the 5D Mark IV offers more robust build quality than the Mark III, with improved weather sealing. However, despite better environmental resistance, the 5D Mark IV is said to be better at dissipating heat, a necessary improvement that comes with the addition of 4K video recording capabilities (more on that later).
Image Quality: More pixels but not too many & better dynamic range
With 22 megapixels, the Canon 5D Mark III offers a decent balance of image resolution and manageable file sizes, yet since its introduction, other manufacturers of full-frame cameras, namely Nikon, Pentax and Sony, have introduced bodies with significantly higher resolution sensors. Canon responded with the 5DS and 5DS R cameras with whopping 50MP full-frame sensors. However, the smaller pixels make the 5DS/R a bit trickier to shoot with, the higher-res images keep the burst rate down, and the larger files can be cumbersome to edit.
The Canon 5D Mark IV, on the other hand, with a newer 30MP full-frame sensor offers a sizable upgrade in resolution compared to the earlier Mark III while also being more competitive against other offerings. The 5D Mark IV is designed for versatility -- for the wedding photographer, the photojournalist, or the landscape photographer -- and the 30MP sensor offers an excellent balance of resolution while keeping the camera's performance nimble.
Image quality overall is very good from both the 5D III and 5D IV, but the improved 30MP sensor and faster DIGIC 6+ image processor offer some nice upgrades over the older camera. For one, dynamic range is much improved, something that the 5D Mark III gets dinged for. Thankfully, the new sensor in the Mark IV offers more latitude, which is great, especially for landscape photographers.
High ISO performance is also excellent, as we'd expect from a full-frame Canon DSLR. However, we don't see a significant difference in higher ISO performance from the Mark III to the Mark IV. Both cameras are great for low-light photography and offer the same expanded ISO range of 50 to 102,400.
Performance: A bit faster burst, impressive buffer & just all-around versatility
While not a camera specifically designed for sports, action and other subjects that require the utmost in continuous burst performance -- for that, turn to something like the 1D X Mark II or the 7D Mark II -- the Canon 5D Mark IV, nevertheless, offers a fairly healthy 7fps burst rate. It's about one frame per second faster than the 5D Mark III, so not a significant upgrade in that regard.
However, the Mark IV really shines when it comes to buffer performance, boasting a sizable increase over its predecessor. Continuous JPEG shooting is practically unlimited; basically, until you fill the memory card, whereas the 5D Mark III's buffer filled after about 63 JPEG images, which certainly isn't shabby.
Autofocus: Same number of AF points, more coverage, better f/8 AF, Dual Pixel
One new feature that the 5D Mark IV introduces is a new Dual Pixel Raw mode, which builds upon Canon's Dual Pixel CMOS AF technology to make use of the split-pixel design to basically capture two images at once. Then, using Canon's DPP software, you can make very subtle tweaks to focus/sharpness as well as bokeh and ghosting. The effect is very subtle, so its usefulness at this time may not warrant the performance penalty. That is to say, the file sizes of Dual Pixel Raw images are almost twice as large, and the burst rate and buffer capacity are significantly reduced while in Dual Pixel Raw mode.
Meanwhile, autofocus performance itself is also very good and up-to-snuff for a professional-class DSLR. While the 5D Mark IV offers the same number of AF points as in the 5D Mark III, at 61, the new camera uses an upgraded AF system. The AF points cover more of the frame, low-light AF is improved, and now all 61 points can focus down to f/8. The latter point here being a major upgrade over the 5D Mark III, which only offered f/8 autofocusing at the center point. Wildlife photographers and others that use supertelephoto lenses and teleconverters are sure to appreciate the improve versatility in this area.
One of the big changes to autofocus on the 5D Mark IV is the inclusion of Dual Pixel CMOS AF. This is a major performance boost for those who like to shoot in live view mode or record lots of video. With its on-sensor phase-detect system, live view AF on the Mark IV is super-quick, smooth and precise. By comparison, the 5D Mark III offered only contrast-detect AF with live view, which was slower and had a tendency to hunt, making for distracting wobbling as focus adjusted (not so great for video).
Video: 4K finally, but it's cumbersome for the casual video shooter
Alongside the new Dual Pixel CMOS AF upgrade, the video features of the 5D Mark IV get a big overhaul compared to its predecessor as well, the primary one being 4K video. Whereas the 5D Mark III and most other EOS cameras top-out at 1080p, the 5D Mark IV is the first non-1D-series or Cinema EOS camera to gain 4K-resolution video, and cinema-friendly DCI 4K (4096 x 2160), at that, in both 30p and 24p flavors. Given the popularity of the 5D-series in the videography world, since the Mark II at least, it makes sense that the latest 5D series would gain sizable upgrades in the video department.
Video quality looks excellent, especially with 4K, but there's a double-edged sword. When shooting 4K, Canon uses a Motion JPEG codec, which offers a very high bitrate, around 500Mbps, meaning the image quality is excellent and with little compression. The downside is that file sizes for 4K video clips are massive, and the high bitrate codec makes it tricky to playback the footage smoothly on even fast computers. For cinematographers, the 5D Mark IV offers high-quality footage, but for casual shooters, 4K might be a bit cumbersome to work with from this camera.
For Full HD, both the Mark IV and Mark III have you covered, though the 5D Mark IV goes up to 60fps rather just 30p in the older model. For capturing video of fast action and sports, the higher frame rate is a plus and makes it easier for higher-quality slow motion video. For even better slow-mo, the Mark IV can record video up to 120fps, but only if you're willing to cut the resolution down to 720p.
Other video amenities, such as mic and headphone jacks as well as clean, uncompressed HDMI output are offered on both cameras, however HMDI output is not 4K for the Mark IV, sadly.
Verdict: Not revolutionary, but a very solid upgrade with many new features
While the design itself is not drastically different, we feel it doesn't need to be. The Canon 5D Mark IV is familiar, comfortable and overall very easy to operate. The addition, too, of built-in Wi-Fi, NFC, and a GPS module are very handy bonuses over the Mark III, as image sharing, remote shooting, and image tracking are all much more streamlined and don't require purchasing add-on hardware now.
If you're wondering whether or not to upgrade from the Mark III, ask yourself if you need the increase in image resolution. If you need really big prints or you want the ability to crop a lot, then the 5DS or 5DS R models might be worth considering. But even still, the bump up to a 30MP full-frame sensor in the Mark IV is a very nice increase in resolving power. Plus, the increase in dynamic range performance is a big plus, both over the 5D Mark III and the 5DS/R models.
On the video side, the 5D Mark IV offers a lot of new features, but 4K footage from the Mark IV is not the easiest to work with, so consider how much video you want or need to shoot. However, the upgrade to 1080/60p is also a nice benefit with the 4th-gen 5D camera.
All in all, the Canon 5D Mark IV offers a sizeable number of upgrades over the previous model, helping both still photographers and videographers alike. Both models are highly versatile, professional-level workhorse cameras, but the 5D Mark IV brings with it a host of modern refinements and welcomed technical improvements.
