Optics and vision conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth. The human eye can distinguish about 10 million colors. The human eye's non-image-forming photosensitive ganglion cells in the retina receive the light signals which affect adjustment of the size of the pupil, regulation and suppression of the hormone melatonin and entrainment of the body clock. Visual acuity is acuteness or clearness of vision, especially form vision, which is dependent on the sharpness of the retinal focus within the eye and the sensitivity
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