ANGIE TAYLOR DESIGN ESSENTIALS CHAPTER 9

TECHNICAL

• VIDEO FORMATS = PAL: europe, stands for phase alternating line, NTSC: united states, canada, japan, SECAM: used in france but generally being phased outing favour of PAL
• FRAME RATE: number of frames transmitted per second, higher frame rate means smoother play back, PAL is 25 fps, NTSC is 29.97, frame rate of film is 24fps. 
• Try to change to multiples of frame rates for easy conversion e.g. 30 to 15frames)
• TIMECODE: a method for measuring time, animation is measured in frames, to work out the length of a project you must divide the number of frames by the working frame rate, SMPTE TIME CODE is divided into hours, minutes, seconds and frames
• FIELDS AND INTERLACING: interlaced and progressive scanning
• PAL 25fps, fields are captured at double the frame rate (50 fields per second), when footage is captured in a computer, the two fields will be mixed together to make up each frame shown on the screen, this results in feathering 
• Adobe After Effects can deinterlace/separate the fields to reduce this 
• Make sure horizontal lines are not too thin as this may cause a flickering effect
• PIXEL ASPECT RATIOS: computers display images using square pixels, pixels used to make an image on a video monitor/TV and rectangular. The shape of the rectangle differs whether it is PAL, NTSC etc
• 788 square pixels: 4:3 PAL (width)
• 576 is the height
• FRAME ASPECT RATIOS: 1. Standard definition TV=4:3 or widescreen 16:9, 2. High definitely TV= square pixels, 16:9 or 1920X1080, 3. Computer Displays = 4:3 but more commonly 5:4
• WIDESCREEN: 16:9, has the same frame rate as 4:3
• Converting can include letter boxing, simulcasting (offering viewers an option), centre cutout, scan and pan
• CODEC: compressor/decompressor
• Spatial and Temporal compression
• CODECS BY MEDIUM: videotape: DV PAL or DV NTSC codecs, these should be used when working with generic DV footage and the footage is going back to tape
• Photoshop and After Effects allows you to change individual colour channels
• TRANSPARENCY: Mattes= an image of movie that tells the compositing software which areas should be transparent and what should be opaque
• ALPHA CHANNELS: black and white, straight (transparency information is only in the alpha channel of the image) and premultiplied (one or all of the RGB channels will have used the alpha information to change the appearance of the image)
• MASKS: user defined shapes that select areas of your image for transparency and opacity, masks can be drawn in After Effects using Bezier drawing tools, can be used to isolate part of your layer