Resolution Chart Comparison (JPEG and RAW)
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). The X-Pro1 uses Fujifilm's unique X-Trans CMOS sensor and therefore doesn't require an anti-aliasing filter, which means that in principle it should be able to deliver resolution closer to its Nyquist limit compared to a Bayer camera with a similar pixel count. Nyquist is indicated in these crops with a red line.
On this page we're looking at both JPEG and RAW resolution. We usually convert the latter using Adobe Camera Raw, but in the case of the X-Pro1 this results in a lot of processing artefacts, so instead we've chosen to use Raw File Converters. We've use the following workflow for this conversion:
- Load RAW file into Raw File Converter
- Set sharpening profile to 'No Sharpness' (all sliders set to 0), all other settings default
- Save file as a TIFF
- Open file to Photoshop
- Apply a Unsharp mask tuned to the camera, here 120%, Radius 0.6, Threshold 0
- Save as a JPEG quality 11 for download
|JPEG (4896 x 3264) 3.4MB||RAW (4896 x 3264) 3.2MB|
There are several points to be made here. Firstly, the X-Pro1 shows visibly higher resolution in this chart test than a conventional 16MP Bayer-type camera such as the Nikon D7000, or even the Sony NEX-5N (which has a particularly weak AA filter). In fact, in terms of resolution it's very close indeed to the 24MP Sony NEX-7 or the Sigma SD1, which uses a 15MP Foveon X3 sensor to record full colour information at every pixel, and therefore (like the X-Pro1) uses no AA filter.
Secondly, these chart shots show very little of the false colour that we'd expect from a Bayer camera with no AA filter - there's a little on the RAW version, but none at all in the JPEG. This supports Fujifilm's claim that the X-Trans CMOS is less susceptible to moiré than a Bayer sensor. Last but not least, the X-Pro1's JPEG processing can deliver just as much resolution as the converted RAW. We were impressed by the X100's JPEG processing, and the X-Pro1 lives up to the same standards.
As we often see for a camera with no AA filter, the X-Pro1 continues to show line structure beyond its Nyquist limit. As usual this is false detail (i.e. it's not an accurate representation of the chart) but in real-world use it often helps give an impression of increased detail anyway.