It's a challenge to produce a sensor that can capture high resolution images and also be read-out quickly enough to produce good video footage. This simple fact explains some of the a7R IV's video specifications.

Key takeaways:

  • Offers both full-width and (roughly) APS-C crops for both 4K and 1080p
  • Cropped footage offers detail benefit, but full-width 4K still looks good
  • Plenty of capture tools: zebras, log profiles (including HLG), peaking
  • Still only 8-bit footage, even when output over HDMI
  • Real-time Tracking of faces and eyes now available while shooting video - but you have to make sure to enable touch-to-track focus
  • Fn menu and button behavior can be configured differently for movie shooting but exposure settings carry over, slowing stills/movie switching

In terms of specifications, the a7R IV looks competitive enough. It can shoot 4K video at up to 30p, either by 'binning' pixels together from the full width of its sensor, or by using over-sampled footage from cropped regions.

Pixel binning doesn't produce as detailed footage as oversampling does, but it at least uses most of the sensor area, so brings the noise benefit of using a large sensor. The 'Super35' crop modes capture around 6000 or 5500 horizontal pixels to produce 24p and 30p video from a 1.6x and 1.8x crop, respectively. This will make it slightly more difficult to get a wide-angle fields-of-view, even with APS-C lenses.

In terms of video tools, the a7R IV is well-equipped: it offers focus peaking, zebra exposure warnings and a choice of log shooting modes. But, compared with previous versions, the a7R IV also has much improved autofocus tracking.

Exposure settings carry over between stills and video shooting

All the video options, including the Log modes, are 8-bit, both internally and over HDMI.

You can define a separate Fn menu and custom button assignments for movie mode, to make it easy to access key functions if you regularly switch back and forth between stills and video shooting. Exposure settings carry over, though, so you'll probably find yourself having to scroll to and from the appropriate shutter speed and aperture values each time you change back and forth.

Sample reel

We shot this sample video using the 24-105mm F4 and 50mm F1.4 Zeiss lenses. Individual clips were shot handheld, using wide-area autofocus and autoexposure, unless otherwise specified.

Studio scene

As with the a7R Mark III, the new camera shoots more detailed footage in its cropped mode than from the sub-sampled full-width region. However, it appears this sampling method has changed, as the new camera appears less prone to aliasing than its predecessor. This puts it ahead of the full-frame output from the high res models from Nikon and Panasonic.

The footage you get if you shoot 30p in Super35/APS-C crop mode is fractionally less detailed than the less-heavily-cropped 24p version, so it'll mainly be challenge of getting a wide-angle field of view that will be the challenge of using 30p mode, rather than any loss of detail or the roughly 0.4EV noise penalty.

It's essentially the opposite story in 1080 mode: footage taken from the full width of the sensor is more detailed and less prone to aliasing than the images from the cropped mode. There's a slight drop in quality in both crops if you need to shoot 1080/120p for slow-mo, but it's unlikely your viewer will notice the difference.