Parallax Error in Photography
In photography, parallax error usually occurs in twin lens reflex cameras. For example, cameras which use a different optical system for the viewfinder and a different lens for image capture.
This is most prominent in extreme close-up / macro photographs and does not impact other long range photos too much. It can be virtually undetectable in panoramas / landscape photographs which have no foreground subjects. However in the case of landscape photographs with a foreground subject, there is significant scope for parallax error. This parallax error can be illustrated by a simple experiment using your finger and a digital camera.
Point-and-shoot cameras normally have a twin lens reflex system with a separate optical viewfinder and lens for image capture, whereas D-SLR's have a single lens reflex system.
Why does parallax error not occur with an SLR or a D-SLR camera?
Both SLRs and D-SLRs are single lens reflex cameras which use a single lens for both viewing photos with the viewfinder, as well as for capturing photos. It is known as a TTL viewing system. (TTL = Through the Lens). Therefore there is no scope for parallax error to occur with either an SLR or a D-SLR.
Read the following Bright Hub article to understand the differences between a point-and-shoot digital camera versus a D-SLR camera and determine which is best for you and your photography needs: Point & Shoot or DSLR Camera - Which is Right for You?