Canon EOS 5D Mark IV review: Approaching perfection

Canon EOS 5D Mark IV review: Autofocus and performance

There was nothing lethargic about this camera in normal use, however. I recorded shot-to-shot times of 0.4 seconds, and continuous mode hit its claimed target of 7fps. It continued until the card was full for JPEGs, and managed 21 RAW frames before slowing to 2fps — a strong result. After I’d enabled continuous autofocus, the camera delivered 5.9fps shooting and did a decent job of tracking moving subjects around the frame. The camera coped exceptionally well in the challenging conditions of a party lit only by moving disco lights.

Tracking autofocus was even more responsive in live view mode, thanks to the dual-pixel sensor, although performance was limited to 2.9fps. It was also slow in the Single drive mode with live view enabled, taking 1.4 seconds between shots.

Canon EOS 5D Mark IV review: Video

It’s exciting to have 4K video and dual-pixel autofocus in the same camera for the first time. I’ve seen 4K consistently outperform 1080p footage for detail levels, even when video projects are published in 1080p format. In the past, Canon SLRs have lagged behind Panasonic and Sony for detail levels in their 1080p videos, so the move to 4K is particularly welcome. Meanwhile, Canon’s dual-pixel technology has shown itself to be extremely effective at delivering smooth, accurate autofocus for video in the Canon EOS 70D, 80D and 7D Mark II. Bringing both of these technologies together in a full-frame camera bodes extremely well.

And, boy, does the Canon EOS 5D Mark IV deliver. Autofocus is smooth and responsive, with the touchscreen making it easy to move the autofocus point during capture, or to select a moving subject to track. Face detection works consistently well, with an option to jump between detected faces in the scene. There’s loads of detail in its 4,096 x 2,160 footage, although pixel for pixel it isn’t quite as crisp as the Sony a7R II or the Panasonic GH4. It also exhibited slightly more noise at faster ISO speeds.

^ 4K video frames aren’t exactly short of detail but the 5D Mark IV’s output isn’t quite as refined as the Panasonic GH4’s or the Sony a7r II’s.

^ Noise levels at fast ISO speeds are a little higher, too. It looks like there’s no noise reduction applied to 4K video.

All three of these cameras use a cropped area in the middle of the sensor for their 4K output. In the GH4 and 5D Mark IV’s cases, it’s so that there’s one pixel on the sensor for each pixel in the 4K video. This sidesteps the need for digital resizing and anti-aliasing of each frame, which would significantly increase processing demands. On the GH4 this results in a 1.2x crop to get 4K (8-megapixel) video frames from its 16-megapixel sensor.

However, the EOS 5D Mark IV uses a 1.74x crop to produce 4K frames from its 30-megapixel sensor. That’s not necessarily a problem itself — after all, the GH4’s sensor has a 2x crop to start with so the 5D Mark IV’s usable sensor area for 4K is still bigger than the GH4’s. However, it does mean that wide-angle lenses won’t be so effective when shooting 4K on the Canon.

Another noteworthy feature is the use of Motion JPEG compression for 4K video. This encodes each frame as a discrete JPEG image, which virtually eliminates compression artefacts even for fast-moving scenes. The downside is the 500Mbits/sec data rate. That equates to 62MB per second, 3.7GB per minute or 225GB per hour of footage. Professional users may welcome the quality this delivers, but there’s a considerable financial and time cost attached to storing and manipulating this much data. For me, the GH4 and a77r II’s 4K footage encoded as 100Mbits/sec AVC format is far more manageable.