Image quality

Out-of-camera JPEG.
Sony 24-70mm F2.8 GM @ 70mm | ISO 640 | 1/400 sec | F2.8
Photo by Dan Bracaglia

With a new 60.2MP sensor, the Sony a7R IV is the highest-resolution full-frame camera we've yet tested - check out how it handles our studio scene.

Key takeaways:

  • Impressive resolution and detail capture
  • Slightly noisier than its predecessor at the highest ISO values
  • Excellent JPEG sharpening and good color, but high ISO noise reduction takes a small step backwards
  • We'd like to see an option for the electronic front-curtain shutter to automatically disable above a certain shutter-speed threshold (leaving EFCS enabled can negatively impact out-of-focus areas of your images)

Studio scene

Our test scene is designed to simulate a variety of textures, colors and detail types you'll encounter in the real world. It also has two illumination modes to see the effect of different lighting conditions.

Raw capture

As you can see straight away, the camera is no slouch when it comes to detail capture - the faint lines within the '20' are more prominent on the a7R Mark IV than any of the other cameras here. Same goes for the face on the other end of the currency - though the a7R IV is now showing some more pronounced moiré on the left side of this crop than the other cameras. Indeed, moiré is a fairly significant problem with all of the cameras used here if you encounter high contrast, high frequency patterns.

As we push the ISO value to 12800 for all the cameras, we can actually see just marginally more noise in the a7R IV than its predecessor. That gap holds through the highest ISO values the cameras offer. However, it's worth noting that we're assessing this noise with resolution normalized to around 36MP for all the cameras in this comparison, and because we're downscaling the a7R IV's 60MP files, they retain noticeably more detail; this should partially make up for the higher noise levels.

JPEG performance

Let's switch over to JPEG mode and glance at color, and honestly, there's not much in it to separate all the cameras here. But for our tastes, we do prefer the deeper yellows of the Nikon Z7 above all, as well as its rendition of the green patch that has a bit more warmth than both of the Sonys. To its credit the Sony cameras render reds quite well compared to the more orange-tinged Nikon red, but blues continue to suffer with a bit of magenta cast.

The a7R IV's default sharpening looks great, with the bottom line of text easily readable, and with far fewer artifacts from the a7R III and Nikon Z7. Areas of very fine detail likewise look pretty spectacular, though the JPEG engines of all the cameras here can't tamp down the worst of the moiré they exhibit. Sharpening of low-contrast detail is also impressive.

In terms of noise reduction, the a7R IV does leave behind a bit more luminance noise than its predecessor, but we don't find it too offensive and is to be expected given the slight noise increase in the underlying Raw. Sony's context-sensitive noise reduction continues to do an admirable job holding onto fine detail, but again, it looks as though there's no real improvement be had over the Mark III. Indeed, some areas show even less fine detail retention than the older model, likely due to heavier noise reduction to combat the slight noise increases in Raw, as well as some color bleed.

Dynamic Range

Sony's a7R IV continues the tradition of the a7R line by exhibiting great dynamic range performance. The sensor uses a 'dual gain' design, which gives you a bit more dynamic range below ISO 320 (more highlight headroom), and a bit better noise performance above it. You can see this in our ISO invariance test. In this test, we choose an exposure appropriate for ISO 6400, and then shoot every ISO from 100 up to 6400 using that exposure, brightening lower ISO Raw files as needed in post. Any differences in noise performance across ISOs must come from the camera (which is then being overcome by the additional amplification being applied at the higher ISO settings).

On the a7R IV, you can see that shooting at ISO 100 or 200 and boosting to ISO 6400 levels shows more noise - but from ISO 400 on up, there's not much real-world difference. This opens up the option of using ISO 320 - 400, instead of much higher ISOs, if you're trying to shoot a low-light scene with bright highlight detail you'd like to capture: there will be a negligible noise cost and you'll retain multiple stops of extra highlight detail by not adding amplification.

The other way of exploiting a large amount of dynamic range is, in bright light, to reduce exposure to capture additional highlights, then brighten the shadow region. Reducing the exposure like this inherently increases the noisiness of your images, since you end up capturing less light and hence are more likely to see the randomness of the light (photon shot noise). However, some cameras perform better than others due to lower read noise. If we compare the a7R IV's images shot this way in our exposure latitude test, we again see an excellent result.

Shutter modes

It's also worth mentioning that the a7R IV allows the use of a variety of shutter modes, including a traditional mechanical shutter, electronic front-curtain shutter ('EFCS', which tames shutter shock), and fully electronic. It's great to have options, but we'd like to see Sony adopt a means of auto-transitioning between these modes, as some competitors have.

EFCS Off | 1/6400 sec | F1.4 EFCS On | 1/6400 sec | F1.4

For example, we'd like to see an option to use EFCS up to a specified shutter speed (say, 1/2000 sec), then switch to a fully mechanical shutter above that, and then switch to an electronic shutter when the mechanical shutter is maxed out. Fujifilm does this on its current cameras, and it's a great way to avoid the truncation of out-of-focus highlights and the general diminution of bokeh that can happen with EFCS and very fast shutter speeds, like using a fast prime lens in daylight. In extreme cases, EFCS can make images shot with very fast apertures appear as though they were taken stopped down.