Evolution of human colour vision similar. Tritanopes are missing the short wavelength sensitive opsins and see short wavelength colours in a green hue and dim compared to other colours. They may also see some short wavelength colours as black. Other perception problems include distinguishing yellow from pink or purple colours being perceived as shades of red. Researchers have found that trichromacy has advantages over dichromacy or anomalous trichromacy at further distances. This is believed to occur because visual cues such as shape decrease for colour vision as distance increases for targets of a smaller size. Using tests for spotting fruit pieces in bushes at distances
Colour co-site sampling moves the sensor by precisely the distance of one pixel and delivers the complete colour information for each detail and with the same sharpness in all three colour channels. Microscanning is essential for the method. 4 (2×2), 16 (4×4) or 36 (6×6) shots can be used for improved colour reproduction. With standard digital cameras, colour images are acquired with only one sensor (see CCD and CMOS sensor). Each pixel of the sensor is sensitive to just one of the three basic colours. For each single pixel on the CCD only one third of the required information is provided and two