Images on this page are of our standard resolution chart which provides for measurement of resolution up to 4000 LPH (Lines Per Picture Height). A value of 20 equates to 2000 lines per picture height. For each camera we use the relevant prime lens (the same one we use for all the other tests in a particular review). The chart is shot at a full range of apertures and the sharpest image selected. Studio light, cameras set to aperture priority (optimum aperture selected), image parameters default. Exposure compensation set to deliver approximately 80% luminance in the white areas.
What we want to show here is how well the camera is able to resolve the detail in our standard test chart compared to the theoretical maximum resolution of the sensor, which for the charts we shoot is easy to work out - it's simply the number of vertical pixels (the chart shows the number of single lines per picture height, the theoretical limit is 1 line per pixel). Beyond this limit (which when talking about line pairs is usually referred to as the Nyquist frequency) the sensor cannot faithfully record image detail and aliasing occurs.
This limit is rarely attained, because the majority of sensors are fitted with anti-aliasing filters. Anti-aliasing filters are designed to reduce unpleasant moiré effects, but in doing so, they also reduce resolution (the relative strength and quality of these filters varies from camera to camera). In theory though, a sensor without an AA filter, when coupled with a 'perfect' lens, will deliver resolution equal to its Nyquist limit. Therefore, even though it may be effectively unattainable with normal equipment in normal shooting situations, an understanding of a sensor's theoretical limit provides a useful benchmark for best possible performance. Nyquist is indicated in these crops with a red line.
On this page we're looking at both JPEG and Raw resolution. For a (more) level playing field we convert the latter using Adobe Camera Raw. Because Adobe Camera Raw applies different levels of sharpening to different cameras (this confirmed) we use the following workflow for these conversions:
Load Raw file into Adobe Camera Raw
Set Sharpness to 0 (all other settings default)
Open file to Photoshop
Apply the Unsharp mask filter tuned to the camera, 200%, Radius 0.6, Threshold 0
Make 100% crops and save the original file at JPEG quality 11 for download
JPEG (5472 x 3648) 4.2MB
Raw (5472 x 3648) 5.8MB
The RX100 is capturing detail comfortably beyond 2600 lph, which is the sort of figure you'd expect of a camera with 3648 vertical pixels. Sony's JPEG engine does its usual good job of suppressing false color, meaning it gives a really impressive result when pointed at a high-contrast test target such as this. Adobe Camera Raw doesn't do such a good job but, with lots of sharpening applied, makes pretty clear what the RX100 is actually capturing. Real-world tests, in which detail is often conveyed with more subtle tones, aren't quite as spectacular as this test chart result would suggest. Even so, it's an impressive result.