The Camera

• Parallax:  is an apparent displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines
•  Pentaprism:  a five-sided reflecting prism used to deviate a beam of light by 90°. The beam reflects inside the prism twice,^[1] allowing the transmission of an image through a right angle without inverting it (that is, without changing the image's handedness) as an ordinary right-angle prism or mirror would
• Pellicle mirror:  pellicle mirror (diminutive of "pellis" - skin or film) is an ultra-thin, ultra-lightweight semi-transparent mirror employed in the light path of an optical instrument, splitting the light beam into two separate beams, both of reduced light intensity. Splitting the beam enables its use for multiple purposes simultaneously, while the thinness of the film greatly reduces reflections commonly associated with glass beam splitters.
• SLR camera: a camera that typically uses a semi-automatic moving mirror system that permits the photographer to see exactly what will be captured by the film or digital imaging system (after a very small delay), as opposed to pre-SLR cameras where the view through the viewfinder could be significantly different from what was captured on film. (The Canon Pellix film camera was an exception wherein the mirror was a fixed beamsplitting pellicle.)
• Aperture: Aperture is a photo editing and management software program that was developed by Apple for the Mac OS X operating system.The software handles a number of tasks common in post-production work such as importing and organizing image files, applying corrective adjustments, displaying slideshows, and printing photographs.
• Shutter: a shutter is a device that allows light to pass for a determined period of time, for the purpose of exposing photographic film or a light-sensitive electronic sensor to light to capture a permanent image of a scene. A shutter can also be used to allow pulses of light to pass outwards, as in a movie projector or signal lamp.
• Exposure: In photography, exposure is the total amount of light allowed to fall on the photographic medium (photographic film or image sensor) during the process of taking a photograph
• Depth of the field: the depth of field (DOF) is the portion of a scene that appears acceptably sharp in the image
• F-stop:  the diameter of the entrance pupil in terms of the focal length of the lens

• Focal lenght: measure of how strongly the system converges (focuses) or diverges (defocuses) light.