Adaptation (eye) opsin photopigment. The various cone cells are maximally sensitive to either short wavelengths (blue light), medium wavelengths (green light), or long wavelengths (red light). Rod photoreceptors only contain one type of photopigment, rhodopsin, which has a peak sensitivity at a wavelength of approximately 530 nanometers which corresponds to blue-green light. A minor mechanism of adaptation is the pupillary light reflex, adjusting the amount of light that reaches the retina. In response to varying ambient light levels, rods and cones of eye function both in isolation and in tandem to adjust the visual system. Changes in the sensitivity of rods and
Kodak Retina Reflex is coupled to the aperture ring - moving the shutter ring automatically moves the aperture ring, so that the same exposure value is maintained. In other words, when in use, the camera is normally locked into one EV setting until the aperture release tab is pressed. Needless to say this can be confusing to those unfamiliar with the camera. All the Retina Reflex cameras are remarkably complex instruments and quite heavy for their size. The Retina Reflex originally sold for $215 USD (app. $1,820 USD in 2014). Approximately 65,000 were made. The Retina Reflex can be fitted with four different