DIGITAL CAMERAS Prof Oakes

Overview Camera history Digital Cameras/Digital Images Image Capture Image Display Frame Rate Progressive and Interlaced scans

Camera Obscura

Camera From “Camera Obscura” – Latin for “Dark Chamber” – An early form of projecting/recording images – Images projected on a wall were traced onto paper A device that records/stores images May be still or moving images May work with visible light or electromagnetic spectrum

Camera The basic Camera consists of: – Enclosed hollow (BODY) – with an opening (APERTURE) for light to enter – A glass (LENS) is used to focus the light entering – and a recording surface (FILM/TAPE/SENSOR)

LENS Most professional cameras have separate lenses. This allows the director more versatility when shooting. The lens captures the light from the subject and brings it into focus on the film or sensor Wide range of FOCAL LENGTHS (distance from center of lens to film/sensor) Wide Angle (Small focal length) 21-35mm Normal (35-70mm) Telephoto (Large focal length) mm

Wide Angle

Lens and Aperture Aperture is the hole or opening in which the light travels through Aperture setting = F-Stop Aperture (F-Stop) and Lens-Type affects the depth of field

Depth of Field In photography and cinematography, depth of field (DOF) is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image. Often confused with Depth of Focus, which is related but different. Lenses determine the range of distances from the camera reproduced clearly

FPS Typical still cameras take one photo per shutter opening and closing (EXPOSURE) Movie cameras (24FPS) Video (29.97 FPS) HD usually 30 or 60 FPS, sometimes 24 PAL (Europe) is 25 FPS

CCD or CMOS Older cameras use photographic film, videotape, or light-sensitive material for recording images Modern cameras use electronic light sensors – CCD (Charged Couple Device) – CMOS (Complementary Metal Oxide Semiconductor) – Memory cards or drives are used for data storage

DIGITAL CAMERAS In a digital camera, light from the thing you are photographing zooms into the camera lens. This incoming "picture" hits the CCD, which breaks it up into millions of pixels. The CCD measures the color and brightness of each pixel and stores it as a number.

DIGITAL CAMERAS A piece of electronic equipment captures the incoming light rays and turns them into electrical signals. CCD or CMOS – 3 Chip Camera has RGB CCD Size of the Sensor is measured in Megapixels (millions of pixels), – 6Megapixels = 6 Million pixels – 3000 x 2000 (height x width) = 6 million Your digital photograph is an enormously long string of numbers describing the exact details of each pixel it contains.

Progressive or Interlaced Progressive or non-interlaced scanning is a method for displaying, storing or transmitting moving images in which all the lines of each frame are drawn in sequence. – Line by Line This is in contrast to the Interlacing used in traditional television systems where only the odd lines, then the even lines of each frame (each image now called a field) are drawn alternately. – Alternating Rows

Exposure Exposure is the amount of light allowed to fall on each area unit of a photographic medium In photography, an exposure generally refers to a single shutter cycle. For example: a long exposure refers to a single, protracted shutter cycle to capture enough low- intensity light. Professional cameras allow the operator to control the exposure manually. Recommended

Under Exposed

Over Exposed

Summary Cameras consist of body, lens, aperture, and sensor Aperture Shutter Speed Exposure Frame Rate I or P Lens: Normal, wide, telephoto