Dynamic range

Dynamic range is the range of tonal values that a camera can represent, from the brightest recorded tone to the darkest usable value. There is, of course, an element of personal taste when it comes to what you consider to be 'usable.'

Rather than just quoting numbers, we try to show the photographic impact.

Key takeaways:

  • The X-T3 shows excellent dynamic range, with a 1/3EV improvement over its predecessor.
  • Electronic shutter imposes a slight cost in DR at low ISOs and in visible noise at higher ISOs.
  • The camera's 'DR' modes make it easy to exploit up to 2EV more of this dynamic range, even if you shoot JPEGs.

Our tests look at DR in two ways: first, our Exposure Latitude test shows the effect of lifting the shadows of images shot with increasingly low exposure (as you would if you were exposing to capture/retain more highlight information).

ISO 320 | 1/6000sec | F2.8 | Fujinon XF 23mm F2
Photo: Dan Bracaglia

However, reducing the exposure itself increases noise levels, which makes it difficult to tell what's happening at the sensor level. This is where our 'ISO Invariance' test comes in. Here we shoot different ISO settings using the same exposure values. This means that any difference in noise must come from the camera. Between the two tests, we can see how tolerant the camera's files are to having addition tonal information pulled up from the shadows into the visible parts of the image.

Exposure Latitude

The X-T3's unusual base ISO makes it difficult to directly compare to its peers (since it means shooting at different shutter speeds). However, by looking at the results of shooting at 1/250 and 1/500sec, you can see that its output is comparable with other cameras (which have been exposed for 1/320sec). In other words, like the best modern cameras, there's plenty of scope for pulling detail from the shadows.

Ultimately the 1/3EV lower base ISO gives the X-T3 1/3EV extra dynamic range, since it can be given more light, which in turn slightly reduces the contribution of shot noise. Switching to electronic shutter mode adds a little noise, which becomes visible only in the deep shadows, causing dynamic range to drop roughly a half stop.

ISO Invariance

There's very little noise cost to shooting at ISO 160, then lightening the image during processing, as opposed to just shooting at ISO 3200. Our collaboration with Bill Claff shows that the X-T3 has a dual gain sensor, which switches from a high DR mode to a lower noise mode at ISO 800, but visually the difference is fairly minor. This means you can keep the ISO setting down and 'underexpose' to protect highlights, then brighten the rest of the image back up, without any significant noise cost.

This isn't that much of a surprise, since this is essentially what the camera's DR modes do (though only with a 1 or 2EV reduction in underlying amplification). Our tests suggest that for very high DR scenes you could get away with going further to retain over 4EV of extra highlights.

Again, shifting to E-shutter mode adds a tiny bit of noise (visible only if you significantly lift the shadows).

Silent shutter

As you'd expect from a camera that can shoot 60 fps video using most of its sensor, the X-T3's silent shutter mode is pretty good. We measured the readout at around 1/40th of a second, which puts it ahead of most of its peers, though still some way behind the 1/160s readout of the specialist chip in the Sony a9 (or the ~1/250s mechanical shutter rate).

The X-T3's electronic shutter mode shows pretty good rolling shutter and hence fewer bands in artificial light. However, any banding can ruin an image, which you can see I'm not happy about.
ISO 1250 | F1.2 | 1/500sec | Fujinon 56mm F1.2R

Even with this relatively fast readout rate, it's still not quick enough to completely avoid rolling shutter effect nor avoid banding when you shoot under flickering artificial lighting. You'll get fewer bands than some other cameras but those bands will still become more prominent at short exposures, and an image with three bands across it will be just as ruined as one with five, so there are still limits on when you can use silent shutter mode.