Macula of retina is seen when viewed from the pupil, as in ophthalmoscopy or retinal photography. The anatomical macula is defined histologically in terms of having two or more layers of ganglion cells. The umbo is the center of the foveola which in turn is located at the center of the fovea. The fovea is located near the center of the macula. It is a small pit that contains the largest concentration of cone cells. The retina contains two types of photosensitive cells, the rod cells and the cone cells. Because the macula is yellow in colour it absorbs excess blue and ultraviolet
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