Bayer Array Sensor
Most DSLRs use sensors based on Bayer Array filtration (above). While resolution is expressed by the number of pixel sites on the sensor, each site can only record one primary color (red, green, or blue). The array assigns 50% of the sites to green, 25% to red, and 25% to blue. In effect, each pixel site records only 1/3 of the information presented by the lens. As all three colors are needed for each pixel, the missing colors need to be created from the existing data. A side-effect of this process is the generation of edge and color artifacts. These artifacts need to be suppressed using additional processing steps, thus further degrading image quality, and dulling the overall color.
Tri-Linear Sensor
Scanning backs, like Better Light, use a tri-linear sensor for image capture. The tri-linear sensor consists of three columns of pixel sites, the number of pixel sites along the height of the column establishes the native pixel count in the vertical dimension. Each column is covered with a filter that allows only one primary color (red, green, or blue) to be recorded by pixel sites within that column. A stepper motor then smoothly moves the sensor horizontally; the number of "steps" the motor takes establishes the pixel count in the horizontal dimension. This combination can record images with a huge number of pixels; however, the main advantage is that actual red, green, and blue color data is captured at every pixel site. Additionally, at native resolution, the raw pixel data is not degraded by interpolation.