Ricoh GR III Camera Review
Moiré, or aliasing, is the term used to describe the artifact sometimes produced on the sensor when repetitive patterns (lines, dots, etc) are present in a scene. When the distance between the elements of the pattern is smaller than the sensor's resolution, strange results will occur, often in the form of wavy patterns, or artificial colors.
From the beginning of digital photography, manufacturers have dealt with moiré by introducing a "low-pass filter" in front of the sensor, usually a properly shaped piece of glass. In 2013, with the K-3, Pentax innovated by removing the physical anti-aliasing filter, instead using the camera's Shake Reduction system to quickly move the sensor in a tunable fashion and control moiré. This innovation is now found on many digital cameras, and the Ricoh GR III is the latest beneficiary.
In this section, we will look at how effective the dynamic anti-aliasing filter is at managing moiré.
For this test, we use a regular pattern of lines with 0.5mm spacing. Positioning the pattern at an angle and at a distance of 0.6 meters in front of the camera, we take pictures with the anti-aliasing filter set to off, level 1 (low) and level 2 (high). The following images show the results.
There is no visible difference, in this particular test, between the low and high settings. However, they are both very different when compared with the first image, with the anti-aliasing filter off. The usefulness of the filter is immediately obvious.
The anti-aliasing filter is effective in reducing moiré. Both the low and high settings performed well in our test.