Projected Images And Projection Systems LL

Projected Images And Projection Systems LL Large Images

Large Images Attract Attention Projected Images And Projection Systems LL Large Images Attract Attention

Generic Projection System

Projection Screens Rear Screen Front Screen

Front Projection Screens Matte Surface Lenticular High Reflectance

Viewing Principles Angle of View < 30Þ

Viewing Principles w = image width 2w min. 4w – comp. proj. 6w – non-computer Minimum/Maximum Viewing Distance

Keystoning

Motion Media 1. In this class we deal with television and film together because they have many similarities. In the course of the discussion, I will also point out a number of differences in the two media. 2. We will talk first about the special attributes of motion media... 3. ...then we will talk about the advantages and limitations of these media. 4. Finally, I will review for you some of the many formats in which you may see these media used. 5. As we go, I'll also be showing you a number of examples of uses of motion media. Unfortunately, because of time limitations, in many cases we won't be able to view entire programs, only bits and pieces to give a feel for a particular application. 6. Before we start the discussion, I am going to show you a program which describes the use of television in what we call non-broadcast applications. As you will see, there are many important ways other that broadcast in which television is used. These may well be some of the kinds of applications with which you are involved if your employer is a corporation, hospital, community agency, or educational institution. 7. SHOW MSTV U-MaticTAPE "INTRO. TO NON-BROADCAST TV" (9:10) NEXT SLIDE: Attributes of Motion Media

Attributes of Motion Media Show Motion Manipulate Time and Space 1. Motion media--film and television--are very complex media which deserve whole courses to understand well. However, for the purposes of this course we will look at the two most basic attributes of these media which distinguish them from still projected media: They show MOTION and they can be used to MANIPULATE TIME AND SPACE. 2. Is there anyone here who has never seen moving images? Maybe I should ask it another way: How many of you have seen moving images? That's interesting. 3. I never have seen a moving image. It's a trick question. Do you know why? Actually, all images which are created by film and television are still images which create the illusion of motion. 4. It's pretty obvious when you look at a reel of film that what you have is a long strip of still images. When they're projected they give the illusion of motion. Much the same is true of television. Television images are made up of rows of dots of light which are different colors and intensities. These rows are scanned thirty times a second and the dots change from scan to scan the image appears to move. But any one full scan is a still picture. 5. Why then, if all television and film are made up of still images, do we see motion? CHANGE SLIDE TO MOTION MEDIA ATTRIBUTES -- SHOW MOTION (Persistance of Vision)

Show Motion Persistance of Vision Re-creating Motion Moving the Motionless 1. Motion is created in our minds because of the phenomenon of "persistance of vision." This simply is the characteristic of our eyes to retain an image for a fraction of a second before replacing it with a new one. This means that we are still "seeing" one still image when the next one appears on the screen, and they blend together. If there is a slight change from one image to the next over a series of images, we perceive those change as continuous motion. 2. If the changes from one still image to the next are too big, we see "jumps" in the image. 3. There are two ways make motion images. One is to record actual movement and re-create it on the screen. That is what happens when a video crew takes a camera out into the field to record a news story, or when a film is made with actors in a studio. 4. The second is to create motion where there wasn't any in reality--using animation. Cartoons may be the most familiar form of animation, but you see it all the time in teaching materials, promotional films, advertising and the like. Animation was first done by artists drawing pictures, and making small changes in each one. 24 drawings are needed for every second of finished film. This technique is still used, but a lot of animation is now done using computer based systems. 5. I'm going to show you two examples of animated sequences. The first is simple animation done to make an instructional point on a relatively low budget. It creates an illusion of motion by dissolving from one scene to the next, rather than changing scenes every frame. SHOW SEGMENT FROM "Geologic Models" (Geophone Seq. 1:30) VHS (JLB) 6. The next segment shows experiments with computer animation which have been done at the Media Lab at MIT (this is a few years old and represents early work in computer animation which has led to virtual reality and other forms) -- SHOW Videodisc Side B, Chapter 13

Manipulate Space and Time Manipulation of Space Manipulation of Time Compression Expansion Arresting Motion 4. Motion media also let us manipulate time. There are three ways that time can be manipulated: By compressing real time to show something which takes a month, for example, in a minute; by expanding time to show something which takes a second in a minute; and by arresting motion as it happens. REVEAL THREE POINTS: 5. Compression of time is called TIME LAPSE. Time lapse sequences are made by taking, for example, one picture every five minutes. At that rate it takes 24 times 5, or 120 minutes (2 hours) to make one second of film . Thus we can see a flower opening or a larva becoming a butterfly. 6. Expansion of time is called SLOW MOTION. Slow motion sequences in film are made by exposing the film at a very high rate--e.g 3,000 frames per second-- and showing it at the normal 24 frames per second. This lets you look at, for example, a bullet approaching, hitting and passing through a light bulb over a period of 20 seconds. 7. Arresting motion is what we see frequently as freeze frame on television. It is also accomplished with an "analyst" projector and film. Generally arresting motion lets us analyze an action bit by bit by projecting it forwards and backwards. It may also be used for special effect, for example, to emphasize an expression at the end of a program sequence. NEXT SLIDE: ADVANTAGES OF MOTION MEDIA

Advantages of Motion Media Visual Continuity Remote Observation Repeated Viewing Dramatize Events REVEAL EACH POINT 1. Motion media make it possible to show an action continuously. If you want to teach someone how to place a simple mattress suture to close a wound, a video sequence can continuously show each step without visual breaks before and after. Unlike a slide program, motion media don't force you to pick one point in time. You can show the entire process without interruption. 2. Another advantage of motion media is that they can be used to record events which otherwise might not be observable because they are in remote or dangerous locations, or are otherwise not directly observable. Many remotely controlled cameras are used to record every space shuttle launch from angles and distances which would not be safe for observation. Still cameras are also used, but they do not document the event as completely . 3. The ability to repeatedly view an event which is recorded on motion media is another advantage. That, of course, is a reason for the space shuttle cameras. It is also the reason for instant replay at football games. 4. Motion Media make it possible to dramatize events. Because they give the audience an impression of reality, scenes can be createdwhich make the audience believe that they are looking at something real rather than something which has been dramatically created. EXAMPLES: 1.Continuous action: Scrubbing and gowning from "Aseptic Technique" 1:50 2. Remote Location: OR scene from "Aseptic Technique" 2:00 3. Repeated Viewing: Beginning through membrane diagram from Residence Hall Maintenance tape 4. Dramatize Events: ClassroomSequence in “Simply Poetry” The use of motion to dramatize events is closely related to the next advantage...their emotional impact... CHANGE TO NEXT "Advantages" SLIDE

Advantages of Motion Media Emotional Impact Command Attention Distance Transmission (TV) Easy/Universal (TV) 4. Partly because they can provide a high degree of reality, motion media are good at making an emotional impact. We can relate to what they show us and we tend to respond to emotional situations. The ability of motion media to dramatize events and have an emotional impact is also enhanced by their ability to alter reality. That is, to present situations in ways the director wants them to be presented. Because we tend to believe that what we see in motion media represents reality, we also respond to the director's manipulated reality. LEAVE SLIDE ON SCREEN EXAMPLE: Emotional Impact: Telethon "Success Story" VHS (JLB) 3:15 5. Motion media command a certain amout of attention by their nature. We tend to stop and focus on the screen because of the motion and accompanying sound. We also tend to continue watching because things are always changing. 6. Television can be transmitted over long distances to diverse audiences. It is the only visual medium available to us now which is capable of this. However, television per se will be superceeded by digital image systems which will combine audio and visual elements in digital transmissions. 7. Television signals and videotapes are easy to use and are virtually universal in the availability of equipment to use them. WE WILL MOVE ON NOW TO SOME LIMITATION OF MOTION MEDIA

Limitations of Motion Media Fixed Pace Expensive Production Advance Planning Large Group Projection (TV) Resolution (TV) 1. Of course, not every application is appropriate for motion media. These are factors which should make you think of using some other medium. The presentation of motion media is at a fixed pace. It is generally not practical to slow down or speed up a program either literally or by stopping it frequently to elaborate on points. Most instructional, informational and motivational programs are based on a narrative, story or other theme which is designed to flow from beginning to end, but if you don't want the whole story told for you by the tape, you may want to use another medium or media combination . 2. Motion media are expensive to produce. That is, good quality motion media are ezpensive to produce. You can make home videos for very little, but once you get into serious film or television production you are talking big bucks. Not only is the equipment expensive, but the staff needed to design and produce these programs also costs plenty. You are used to multi-million dollar Hollywood productions. Typical corporate and educational costs for production are at least $2,000/finished program minute. That's at least $40,000 for a 20-minute training program. 3. Using films and videotapes requires advanced planning. Since most institutions can't afford to own a copy of every program they use, these programs are often rented. This means that the program isn't on the shelf within your grasp whenever you want to use it, like a set of slides or a slide/tape might be. And, of course, advance planning is even more essential if you need to produce your own motion media. 4. Although film is an excellent medium for presentation to large groups, television projection still has many limitations. It is expensive, the image is not as bright as a film image, ... 5. ...and, as we discussed earlier, the resolution of projectedtelevision images is not nearly as good as film. NEXT SLIDES: Resolution, than Film Formats, then Television Formats

Resolution of Film and Television TV : 525 lines HDTV: 1,125 lines 16mm Film : 2,000 lines 35mm Film : 4,000 lines 1. The technical clarity of film and television images is generally expressed as resolution. Both types of image are made up of dots--the dots in film images represent the crystaline grain structure of the film's emulsion, and the dots in television images are created by a mask on the display tube. Resolution is given as the number of lines of dots which theoretically make up the image across the horizontal dimension. 2. The greater the number of lines which make up the image, the greater the detail or clarity of the image. The better the resolution. 3. As you can see by this table, the resolution of television images is far less than that of film images. There are techniques, not yet in use outside research labs which can provide a television resolution as good as or better than 35mm film, using digital processing techniques. But for the time being if you want to see really good images go to the movies.

Formats – Film 16mm 35 mm 70mm 1. We have talked about formats with each medium. There are also several formats in which film is available. 2. 16mm is the standard format in which instructional and informational films are released. That is thekind of film you worked with in the LRC. 3. Larger films, 35mm and 70mm sizes, are used for theatrical release. NEXT SLIDE: Video Formats

Formats – Television Professional Formats – 2” Quad 1” “C” Format 1/2” BetaCam SP, M2 1/2” Digital (D2) Industrial/Educational Formats – 1/2” VHS S-VHS 8mm Hi-8 3/4” U-Matic Distribution Format – VHS 1. There are zillions of videotape formats, so for purposes of simplification I will mention only a few of the most common. They can be grouped generally into three categories: Professional, Industrial/Educational, and Distribution formats. 2. PROFESSIONAL FORMATS –  The broadcast standard for many years, and still found in many television stations, is what's called 2" Quad tape. As the name implies, it is 2" wide. It requires a recorder the size of two or three file cabinets, and is rapidly being replaced by smaller formats.\ 3. Now the standard of quality for videotape, the 1" C Format is the most widely used format by professional production houses and larger industrial and educational instituions. 4. At one time considered the format for education and corporate applications, 3/4" U-Matic videotape is still used by many middle and smaller size companies and schools. It provides a better quality picture than 1/2" tape, and is a lot less expensive to use than the larger formats. 5. 1/2" videotape is generally thought of as the consumer or home video format. It is also very important as the medium of distribution for most kinds of programs, regardless of the format in which they were recorded. VHS is quickly taking over as the overwhelming favorite among the 1/2" formats. 6. 8mm video was developed and marketed by Kodak at the wrong time. The competition it found from the VHS market which was at its most rapid period of growth when 8mm was introduced, was too much to overcome. 8mm is still around, and may come back sometime, but don't hold your breath.

MULTIMEDIA Presentation systems or programs (materials) which incorporate a combination of media formats, usually including both aural and visual elements.

Examples of Multimedia Systems Slide/Tape Programmable Control Systems Multimedia Classroom Control Systems Multimedia Computer Workstations

Examples of Common Media Formats for Multimedia Audio tape Videotape Slides Video Disc Compact Audio Disc (CD) CD ROM Digital Data Storage

Slide/Tape Programs Group presentaion Individual Presentation

Advantages of Slide/Tape Consistent narrative information Mixing of non-verbal audio (music, natural, fx) Audio/visual information linked Relatively easy and inexpensive to produce locally

Limitations of Slide/Tape Special equipment set-up Sound and visual can get out of sync Provides limited visual movement (not true motion)

Synchronization Principle: record pulses on audiotape at point where visual is to change Demonstrate use of sync audio tape machine with slide projector

Synchronization Audible Pulses: Tones on the audio track which can be heard by the viewer, cueing him/her to manually advance the slides. Inaudible Pulses: Tones on an audio track other than the program track (1000 Hz) which advance the slides automatically.

Multi-image Presentation Multi-image: Images from more than one projection source displayed on one or more screens in sequence or simultaneously Multi-screen: Multi-image presention which uses more than one screen

Some common uses of Multi-image Education/training Informational presentations Motivational presentations Entertainment Education/training, especially in technical and scientific presentations, but applicable in almost all Informational presentations at public attractions (e.g. historic sites, state parks, museums, worlds fairs. . .) Motivational presentations for product introductions, political conventions, worlds fairs . . . Entertainment at amusement parks (Disney World, etc.)

Reasons for using multi-image Compare/contrast Continuity (build) Maintain relationships Special effects Simulate motion

Common Multi-image Formats Single Screen Side-by-Side Multiple Screens/Multiple projectors Single Screen Two projector dissolve (intro. dissolve units) Three projector dissolve Side-by-Side (two images, two projectors) Multiple Screens/Multiple projectors programmers)

Electronic Multimedia and Internet CD ROM QuickTime Virtual Reality RealAudio Netscape – Web Sites CD ROM African Collection QuickTime Virtual Reality Gage Technology FAQ’s–also example of Director program RealAudio Audio over the Internet Netscape – Web Sites Selected Web sites