3 The Camera
I Can . . . • Define multimedia terms • digital camera • CCD – Charge-coupled device • Convex • Focal Point • Focal Length • Identify the four distinct parts of a camera • Identify how focal length is measured • Identify the four types of lens • Identify the two types of zoom
I Can . . . • Explain the differences between the various video cameras available. • Identify each part of a video camera and note the corresponding function. • Differentiate between the focal length and the focal point related to a zoom lens. • Explain the interrelationship between f-stops, the iris, and aperture in controlling light.
Camera • Originated from the term Camera obscura • Latin for “Dark Chamber”
Most camera operators can unpack their hardware and begin recording right away But - Results are often unsatisfying Making a successful photo or video requires knowing: How to operate the equipment How to record good-quality photos, videos, and audio How to record footage that can be edited effectively Photography/Video Production
Types of Cameras • Still Cameras • Studio camera • Camcorder • Convertible camera
Camera Types • Instant/disposable – takes photos by capturing light onto photographic film or plate; film preinstalled, meant to be used just once – focus fixed lens – some have a flash – some are even waterproof • Digital – takes photos by recording images on an electronic image sensor • SLR – Single-lens Reflex – camera that typically uses a mirror & prism system that permits the photographer to view through the lens and see exactly what will be captured (contrary to a viewfinder camera – where it could be different) • DSLR – Digital Single-lens Reflex – (or Digital SLR) – digital cameras combining the optics and the mechanisms of an SLR with a digital imaging sensor (as opposed to photographic film) • Video – camcorder, professional, phone, etc
Studio Camera • A television camera placed on a tripod or studio pedestal for exclusive use within the studio. • Remains in studio • Unsuitable for field work because of: • Size • Weight • Paired with • Camera control unit (CCU)or • Remote control unit (RCU)
Camera Control Unit (CCU) • A piece of equipment that controls various attributes of the video signal sent from the camera to the video tape recorder, and is usually placed in the control room or the master control room. Also commonly called a remote control unit (RCU).
CCU/RCU • Two names for the same device • Controls technical specifications of video signal from camera to match images from all cameras • Color • Tint • Contrast • Brightness • Iris
Camcorder • Contains camera and recorder in one unit • Lightweight and portable • Sits on tripod or rests on operator’s shoulder • Records on variety of digital tape and other media • Usually can be directly connected to editor to download footage • Generally used by consumers
Camcorders • Earliest types – recorded analog onto videotape cassettes • Invention of the portable recorder led to the elimination of “film at eleven”
Convertible Camera • Camcorder that can be accessorized to become studio camera • Larger viewfinder • Rear controls for lens operation • CCU/RCU may be added • Less expensive than studio camera and more versatile
Parts of a Camera • Many parts are interchangeable, allowing user to customize camera to exact needs • Lens • Viewfinder/LCD • Storage/Medium • Imaging Device/Camera head
Camera Lens • Assembly of glass discs on front of camera through which light passes into camera • Job – to direct light to the imaging device
The Lens • Video lenses are convex – thin along the edges and wider in the middle • Light enters and covers the lens, but the shape focuses the light to a single point – focal point when it leaves the lens • Place where the image inverts inside of lens • Wherever actual zoom lens is located
Camera Lens • Focus–occurs when adjoining areas of contrast are as sharp as possible • Auto-focus–optional electrical circuit that tries to automatically keep image focused • Professionals do not use auto-focus • Auto-focus removes possibility of creative focus techniques
Focal Length • Distance (in millimeters) between focal point and back of lens • Lenses are referred to as: • 50mm • 400mm, etc.
Focal Length • If you change the distance between the lens and the focal point, you change the area that the lens can see - the focal length • The distance between the lens and the imaging device when the image is in focus
Focal Length • A shorter/smaller focal length has a wider field of vision • A longer focal length has a narrower field of vision 70 mm 210 mm 28 mm 50 mm
Lens Categories • Normal – sees what the human eye would • 50mm • Wide-angle (shorter focal length) • < 50mm • Telephoto (longer focal length) • > 50mm • Zoom – variable focal length (can do all 3)
Zoom Lens • Allows smooth transition from close-up to wide-angle shot • Accomplished by moving zoom ring on lens assembly (or W/T button) • Transition from wide-angle to close-up—called zoom in,or tighten • Transition from close-up to wide-angle—called zoom out,or widen
Optical & Digital Zoom • Many cameras offer optical and digital zoom capabilities • 30X optical • 1200X digital • What does this mean?? • These numbers are ratios • The lens can enlarge the image by 30 or 1200 times • You can get a really good close-up
Optical & Digital Zoom • Optical – uses the lens elements to enlarge the image • The “good” zoom • Difficult to hold the image steady w/o using a tripod or image stabilization
Optical & Digital Zoom • Digital – enlarging the pixels in the middle of the image • Software based zoom - The “bad” zoom (blurry or poor) • Have fewer and fewer pixels, but the individual pixels are bigger and bigger
Variable Focal Length Lens • Another name for zoom lens • Since actual zoom lens moves back and forth within zoom assembly, and since zoom lens is always focal point, distance between zoom lens and back of lens varies • Therefore, zoom lens is variable focal length lens
Viewfinder • Small video screen that lets camera operator see image that camera is obtaining • 1” screen with eye cup for operator with camera on shoulder • Small screen (3.4”/4.5”) that unfolds from side of camera used when camera is on tripod • Larger screen (5”–7”) separate unit attaches above studio camera head • Professional cameras are generally black and white (eye more sensitive to light/dark rather than color)
Viewfinder Display Information • Most cameras will display the following in some fashion: • Battery status • Tape/media status • Counter (hours, minutes, seconds, and frames) • Record symbol • White balance (outdoor/indoor or automatic) • Date • Zoom level • Etc.
Diopter Adjustment • Adjusts magnification on 1” viewfinder for operators who wear glasses
Storage/Medium • Film camera • Film • Digital camera • SD Cards • HDD (Hard Drives) • Tape
Camera Head • Actual camera • Contains all the electronics needed to capture image • Light enters camera and hits target • Target is front of charge coupled device (CCD) • CCD is the imaging device that converts light to electrical signal • Stored on tapes, memory cards, or hard drives • Professional quality camera has three CCDs • Consumer quality camera has one CCD
Additional Features • Gain Control • Zebra Stripes • Aperture • F-stops • Iris • Shutter
Gain Control • Feature found on higher-end cameras • Allows strength of video signal to be increased or decreased • Used when image is too dark or too bright • Has negative effects • Entire image becomes increasingly grainy • Brighter areas begin to glow unnaturally • Should not be activated without supervisor approval
Zebra Stripes • Alert for camera operator • Stripes only appear on viewfinder when camera is not recording • Diagonal black and white lines in areas of viewfinder that are beyond set limits of video brightness • Any area with zebra stripes will glow • Action is recommended to eliminate stripes
About Exposure • Go outside with a mirror when the sun is out • Look at your eyes in the mirror • How big are your pupils • Go back inside and look again • How big are your pupils now?
Exposure • The lens controls the amount of light that reaches the imaging device - the exposure • (Through shutter speed and aperture) • Human Eye • Pupils shrink down if plenty of light • Pupils get larger if less light • Camera lens serves the same purpose • One part of the camera that controls the amount of light is the aperture (lens diaphragm)
Shutter Speed • The amount of time that the shutter is open • Measured in seconds or fractions of seconds • The bigger the denominator, the faster the speed • 1/1000 is much faster than 1/30 • Default for Panasonic is 1/60 • Anything slower than 1/60 is very difficult to use without getting camera shake • Must use a tripod or image stabilization • Usually double with each setting • 1/500, 1/250, 1/125, 1/60, 1/30, 1/15, 1/8, etc
Shutter Speed • When shooting an image, consider how you want to capture movement • Freezing the moment • Letting the moving object intentionally blur
Aperture • The opening, adjusted by the iris, through which light passes into the lens. • Actual hole or opening in lens • Large hole lets in much light (fast lens) • Small hole lets in little light (slow lens)
The Exposure Triangle • ISO – how sensitive a film is to light or the sensitivity of the image sensor • The lower the number the less sensitive to light and the finer the grain • Shutter Speed • Aperture
ISO • Left – ISO of 100 Right – ISO of 3200 ISO of 100 is considered “normal” – provides crisp shots with little grain/noise
The Exposure Triangle Metaphor The Window • Imagine your camera is like a window with shutters that open and close. • Aperture is the size of the window. If it’s bigger more light gets through and the room is brighter. • Shutter Speed is the amount of time that the shutters of the window are open. The longer you leave them open the more that comes in. • Now imagine that you’re inside the room and are wearing sunglasses (hopefully this isn’t too much of a stretch). Your eyes become desensitized to the light that comes in (it’s like a low ISO).
The Exposure Triangle Metaphor The Window • There are a number of ways of increasing the amount of light in the room (or at least how much it seems that there is. You could increase the time that the shutters are open (decrease shutter speed), you could increase the size of the window (increase aperture) or you could take off your sunglasses (make the ISO larger).
Iris • A component of a lens that is comprised of blades that physically expand and contract, adjusting the aperture size • Metal blades form circle (the aperture hole) • High blades create thick circle and small hole • Low blades create thin circle and large hole • Controls amount of light that reaches back of lens/target of camera • Smaller the number – the larger the hole