Pixel Shift image quality

16-shot pixel shift, for higher resolution (240MP) and to cancel the effect of the Bayer CFA. Exposed for the highlights, then tone-mapped in ACR.
Tamron 17-28mm F2.8 @ 17mm | ISO 100 | 1/50 sec | F5.6
Photo by Rishi Sanyal

The a7R IV improves upon its predecessor's high-resolution mode, dubbed Pixel Shift, by offering up to 16 captures to yield up to 240MP files. It's a nice feature to have, but is only useful in very limited circumstances - and unfortunately, Sony's implementation is currently the weakest on the market among competitors' high-resolution capture.

Key takeaways:

  • Users can choose to capture 4 shots to cancel the Bayer filter array and get better detail from 60.2MP files, or capture 16 shots and combine them on an editing computer for 240MP files
  • Works with strobes, but the fastest shutter speed available is 1/8 sec
  • No motion-correction severely limits the range of subjects it can be used with
  • Cumbersome 'Imaging Edge' software is required for best results (the camera cannot combine its images internally)

New to the a7R IV is the ability to combine up to 16 images for 240MP files, similar to how the Panasonic Lumix S1R combines 8 of its 47MP images to produce 187MP files. The older a7R III and Pentax K-1 Mark II use a four-image pixel shift feature to cancel out the Bayer filter array, yielding impressively sharp and richly detailed files, but without increasing spatial resolution.

Glance around the scene and, despite the images appearing just slightly soft, you're still confronted with a nearly absurd amount of detail. But look carefully at those two previous states, and you'll see the a7R IV seems to suffer from some odd cross-hatching artifacts on contrasty and diagonal edges. The Siemens Star shows this off particularly well. It's worth noting that Sony's own software provides an option that lets you smooth away these glitches. Find more information about this and how we processed the test scene here.

In the end, this will be a useful feature for those doing still-life work, or reproducing other works of art, but in its current state, the lack of motion correction, the artifacting and the fact that you have to combine the files on a computer instead of having them ready-made by the camera will limit its appeal. The Panasonic's high-res mode comes off as a much more polished implementation. That said, downsize all these images to 36-42MP, and all these cameras produce excellent results all across the scene. Plus, when the results are normalized, you get an impressive noise benefit at higher ISO values, stemming from having combined multiple images.