|
Viewfinder OpticsFigure 2 shows the various components of the viewfinder optics. The optics, shown on the left, are comprised of two lenses: an eyepiece that is attached to Bigshot's back cover and an objective lens that is mounted on Bigshot's front side.
The way that the viewfinder works with the eye to form images is very similar to the way that Bigshot's wide angle lens works with the primary imaging lens to form wide angle images. As described in the Polyoptic Wheel section, the role of the wide angle lens is to widen Bigshot's field of view, and the task of focusing incoming light to form an image is left to the imaging lens to perform. Likewise, the role of the viewfinder is to give the photographer a field of view similar to Bigshot's, and the task of focusing incoming light to form an image is left to the eye's lens to perform. Since neither the wide angle lens nor the viewfinder focus light, they are both examples of afocal systems [1]. The viewfinder is not in the same place as the imaging lens, so there is a small difference between what the photographer sees through the viewfinder and what the camera sees through the imaging lens. This "parallax [2] error" is most obvious when taking pictures of things that are nearby, so what the photographer sees when taking close-up photos will be a little different than what he or she will see in the photo itself. The effect of the parallax error is almost completely unnoticeable when taking photos from a distance, however.
References
|
