Visual Technologies (PDF)

Visual Technologies Light Behavior Sunlight: Sun creates white light that emits from a small source of light which creates sharp-edged shadows Skylight: Blue sky creates color cast light that emits from a very large source of light which creates soft shadows Bounced lig...

Visual Technologies Light Behavior Sunlight: Sun creates white light that emits from a small source of light which creates sharp-edged shadows Skylight: Blue sky creates color cast light that emits from a very large source of light which creates soft shadows Bounced light: light that is reflected, the color of the reflected light is blue cause of the blue sky. Surfaces that are closer together receive more of the reflected light Terminator : the area between the main light and the fill light ( reflected light from the ground ) Darkest area on the object, effect of the contrast. Sun Light Visible light is made up out of pure energy (photons ) which have different wavelengths depending on their color The shorter the wavelength the bluer it becomes, the longer the wavelength the more red it becomes White light is composed of a spectrum of colors Diffuse Scattering When Light travels through the atmosphere, the shorter light wavelengths become scattered in different directions Radiance / Bounce Light When light hits the surface it either bounces or its absorbed by it depending on the color of the surface A white object will reflect all wavelengths equally and a black object will absorb them Only visible when there is a great deal of light White Balance Color temperature at which white objects actually look white The best way to test it is to set a digital cameras white balance to daylight Three-point Lighting Bright main light coming from one side, dim fill light coming from the opposite side, and a back light behind the subject Key or main light is the main illumination that defines the most visible lighting and shadows Fill light softens and extends the illumination provided by the key light it can simulate sky light Rim or back light creates a bright line around the edge of the object to separate the object from the background Front light Directly behind the observer’s point of view and makes the object look flat Some areas might look washed out Side light Right or left from the observer’s point of view and helps show the texture and makes the object feel three-dimensional Some areas can be lost in the shadow Back lighting Pointed in the observer’s direction made to create a silhouette from our object Usually a lot of shadow Top lighting Pointed down at the object common in over cast daylight creates a mysterious and a dramatic shadow Can be used to create an uncomfortable feeling Bottom lighting Pointed up at the object usually when above a campfire or flashlight creates an unusual effect and a strange appearance The rarity of this effect can be used for creative purposes Shadow types Form shadow: shaded areas on a surface where the light can’t reach Cast shadow: shadows projected by an object onto a surface Shadow plays an important role in your artwork Secondary light Shadows are filled with secondary light Form shadow on the object is getting fill light coming from the ground as well as the sly Color in shadows Shadows are themselves illuminated by what is known as fill light, usually a secondary or reflected light source Shadows are rarely black and generally contain light and color Form shadow Form shadow gives an object depth and helps convey the form of the object it also reveals texture To create this effect use side lighting Ambient occlusion In 3D rendering ambient occlusion adds a layer of realism by darkening surfaces that are adjacent to others and creating a shadow around the area where they meet creating a sense of depth As the objects get close to each other less light is available so the surface darkens Light source The most important factor is the size and distance of the light source A small distant light will cast hard edged shadow A large light will case soft shadows Light size & proximity Small or distant light source the rays of light have little or no overlap giving the shadow crisp hard edges Large adject light source the light rays overlap creating a softer edge Umbra: The darkest part of the shadow Penumbra: partially shaded outer region of the shadow Reaction to light (Theory) Diffuse reflection – Light reflected is heavily scattered (diffused) by the surface Specular (direct) reflection – Light reflected at the same angle just like a mirror Transparency / Translucency Incandescence (emitting light) Reaction to light (Real) Specular & Diffuse – Materials can be polished to eliminate irregularities this makes the material specular and diffuse Non-Diffuse – Some materials do not cause diffuse for example: Metal, Gasses, Glass… Non-Diffuse Diffusion – Some non-diffuse materials it can cause the light to diffuse anyways because of the roughness on the surface Sharp Specular Diffusion – This happens when the material contains just a little % secularity Frensel Effect The greater the angle relative to the surface normal, the stronger the reflection will be At the maximum glancing angle, all smooth surfaces will reflect near 100 percent in a specular fashion, even if non metallic This is an optical effect and not a real specular reflection Refraction Instead of reflecting or absorbing light refraction bends the light on the way Transparent – almost all the light that meets transparent materials passes directly through them Translucent – When light encounters translucent objects some of it passes directly through them but some of it does not Opaque – An object that is not capable of letting light pass through it is called Opaque Color Color spectrum – The surface absorbs some of the wavelengths and reflects others Color properties – Hue, Saturation and Intensity or lightness Gamut – limited range of colors for example our screens can only show the RGB color gamut Hue – synonymous to the world color and represents the base color itself on the color wheel and it depends on the object’s hue and the light sources hue Saturation – how pure or intense the given hue is, Light that is reflected will be less intense and pure than light that has been directly emitted Value – The brightness of a hue, it indicates the quantity of the light reflected Systems & Harmony RGB system – anything that emits or radiates light, all colors added give white and no color give black  CYMK system – works on the basis of reflected light created for printing because white is the natural background of paper we have to do the opposite to give out the same colors Monochromatic – Shades of a single hue Complementary – Hue’s opposite to each other on the color wheel Analogous – Neighbor to each other on the color wheel Triadic – Three colors arranged evenly spaced around the color wheel Discordance – Deviate from the balanced movie color scheme to refocus attention Rule of thirds Positioning the most important elements of your image at these intersections points produces a much more natural image Off-center composition is pleasing to the eye because its typically where the eyes go first Golden triangle Done by drawing a diagonal line across the image with two additional lines from the remaining corners intersecting the first line at 90 degrees It creates a balanced composition Golden Ratio Artists using this ratio are often after perhaps the most “natural” balance to their compositions The ratio itself is 1.618 also known as phi Leading lines Lines that lead the eye to key elements in the scene Artists use this technique to direct the viewer’s eye Frame within frame Finding any shape or visual element in your scene that can frame your subject within the shot Angles Point of view given to the viewer Can have a dramatic effect on the composition Parallel angles Simply means parallel to the ground and always aligned with the ground Different camera heights for different effects Perpendicular angles Intersecting the ground at 90 degrees so straight down or up Also called Gods eye view Diagonal angles Between 0 and 90 degrees to the ground creates an extra layer of perspective Much more opportunity to create a bias Texture Less about arrangement and more about the tactile aspects of an image It give the composition a tangible aspect by appealing to our sense of touch Patterns Humans are pattern-seeking animals Composing an image with patterns has an immediate effect to draw us in Repetition Either uniform and orderly or random and chaotic Forces us to acknowledge the focal point Space Every work of art works with space How you use the space available determines the outcome of your composition Positive space Used to refer to the areas of interest and focus Patterns can become positive space Negative space The space surrounding a subject, typically empty and lacks details to simplify an image Can be used for psychological effect Fill the frame Positive space takes up most or all the frame Close up that fills the frame Depth The use of foreground, middle ground and background is called layering and creates depth Making use of a vanishing point to make things smaller the further away you get Deep space composition All three planes are represented, in focus, and included in the story Symmetrical balance Visual elements are arranged on both sides of a horizontal or vertical so there is equal weight It can direct the viewer’s eye to a focal point Asymmetrical balance Unequal weight on both sides of a composition The juxtaposition of two unlike things makes the viewers innately want to compare and contrast them Radial balance Arrangement of visual elements around a central point Often symmetrical balance that is circular Contrast in subjects Sometimes contrast can be a statement using contrasting subjects What the subjects are depends on what you want to communicate Contrast in lighting Light and shadow add immense depth and dimension The style later became known as chiaroscuro Contrast in color It can hold meaning and can make the image more striking Using complementary colors creates contrast Tone Consideration of bright and dark and the feeling it exudes Rather that focusing on exposure it is specifically toward the tones of black white and everything in between Global tone Looking at the entire image which might be a consistent color or a combination of many Local tone Focusing only on a portion of the image, where one area is more distinctly different from the rest Exposure Aperture Lens adjustment that affects the light and depth of field A large aperture lets more light that will hit the camera sensor, where a small aperture let sin less light Aperture & Exposure The size of the aperture will dictate how exposed your shot will be The more light that comes through the lens, the brighter the image will be Depth of field How blurry or sharp the area is in front of behind your subject Changing the f/stop affects the depth of field Shallow DoF A low f/stop creates larger foreground and background blur Deeper DoF By closing your aperture to let in less light, you can create a deeper focus ISO How sensitive a digital cameras sensor is to light Lower ISO value less sensitive, a higher ISO value more sensitive Image Noise Increasing your ISO may brighten up your shot but it will add image noise Sensor becomes mor sensitive to the light Avoiding Noise You want your ISO as low as possible A large dynamic range results in more detail and color range, so keep the shot as close as possible to a native ISO Shutter Speed How long the sensor of the camera is exposed to light, measured in fractions of a second It affects the exposure but also motion blur Motion Blur Downside of a longer shutter speed is motion blur Fast shutter speeds let in less light 180 Degree Shutter rule Shutter speed should generally be set to double your frame rate Cinematic shutter speed Correct exposure Over/Under Overexposure is when too much lights hits the camera sensor Underexposure is when not enough light hits the camera sensor Method 1 Step 1 – set shutter speed to double the frame rate Step 2 – Adjust aperture to the f/stop you want artistically Step 3 – Set your ISO as close as possible to your cameras Native ISO If the ISO is all the way up but the image is dark or noisy, drop it back down and return your aperture to let in more light Method 2 Use a light meter Proper settings for aperture, ISO and shutter speed Method 3 Bracketing, shooting the same Image multiple times using different camera setting resulting in different exposures Can also be used to merge photos of the same image with different exposures Calculating stops Why stops? Compensate a change in one parameter with a change in another There has to be some sort of correlation between the three parameters Exposure It doesn’t matter which parameters you change A stop is a two-times increase or decrease of light gathered during exposure Aperture stop f/1.4 lets in twice more light than f/2, eight more times than f/4, … Shutter speed stop Defines the period of time during which light is allowed to go through ISO stop Divide or multiply by 2 to add a stop or go one stop down Camera obscure Old cameras projected the image onto another surface and then they drew the image Niepce 1830 A portable camera obscura to expose a pewter plate coated with bltumen to light Kodak 1880 A flexible roll film that did not require the constant changing of solid plates First camera was inexpensive enough for the average person to afford War 1930 Life as it occurred rather than staged portrait Polaroid 1960 Develop film inside the camera in less than a minute Compact camera 1970 Image control decisions on their own Digital age 1990 Cameras that stored images electronically Focal length A calculation of an optical distance from the point where light rays converge to form a sharp image of an object to the digital sensor It tells us the angle of view and the magnification Image sensor If the sensor covers the full area of the image circle, It is called a “full- frame sensor” and if it covers a smaller portion that throws away or crops part of the Image, It is called a “crop sensor” Crop factor “Crop factor” is the ratio of the sensor size to 35mm / full-frame You take the provided crop factor number, multiply it with the focal length of the lens and you get the equivalent focal length relative to 35mm film / full-frame Prime lens Fixed focal length lens that doesn’t let you zoom in or out Zoom lens Any lens with a variable focal length Lens types Fisheye 8 - 16 mm Wide angle 24 – 35 mm Standard 35-50 mm Telephoto 70 mm & Up Macro Lens (used for really close pictures) Aspect ratio An aspect ratio is just as ratio, which means it’s a comparison of two numbers Shots Establishing shot (introductory component to the location) Master shot (capture the scene playing in its entirety) WS = Wide Shot (special relationship to the objects) FS = Full shot (head to toe) MFS = Medium full shot CS = Cowboy (from the waist up) MS = Medium shot ( from bellow the chest to the head) MCU = Medium close-up shot (Mid chest to the head) CU = Close-up shot (Arranged at eye level) ECU = Extreme close-up shot (Frames the subject to isolate an area) Camera framing Single shot (one character in the shot) Two shot (two characters in the shot) Three shot, Four shot, Crowd shot,… OTS = Over the shoulder shot POV = point of view shot Insert shot ( Object ) Camera movement The pan ( 180 turn) The tilt (tilts the camera vertically) The zoom (zooms in) The dolly ( Slow movement The pedestal movement Crane or boom Steadicam ( on human no shake) Handheld (shake feeling) Rack focus ( Focus with the lens) Resolution Your image is like a mosaic formed by small tiles, which are called pixels Pixel count = Number of pixels that form your photo To calculate the resolution multiply the length by the height Divide it by a million to convert it into megapixels Pixel density = expressed in dpi which is the acronym for dots / pixels per inch Bits 1 bit = 0 & 1 (2 states) 1 bit = 2 colors, 2 bit = 4 colors, 3 bit = 8 colors, … BPC = all the options for Red, Green and Blue (color depth) BPP = The range of numbers that we have to represent a color of a pixel (bit depth Colors = BPC x BPC x BPC (because we have 3 channels per pixel) Lossless Compression With lossless compression, every single bit of data that was originally in the file remains after the file is uncompressed. All of the information is completely restored. Lossy Compression Reduces a file by permanently eliminating certain information, especially redundant information. When the file is uncompressed, only a part of the original information is still there Image formats Jpeg = Lossy, 24-bit with vibrant colors, no transparency, has cmyk Png = Lossless, 8-bit, transparency, no cmyk Gif = Lossless, animation, transparency Tiff = lossy or lossless, original information, supports layers Video encoding Methods of optimizing digital video files for different platforms, programs and devices A codec and a container Storage availability, quality of video output, and compatibility with different video players or programs Codec A codec is a software that compresses your video so it can be stored and played back The bit rate, which refers to the amount of data stored for each second of media that is played Using either lossy or lossless compression Container Container is like a box that contains your video, audio and metadata MP4, AVI, MOV, h.264 Interframe prediction One frame is compared with a reference frame and only pixels that have changed with respect to the reference frame are coded Frame rate Progressive = line by line onto the tape in a sequential order Interlaced = laid down in and alternating order Color spaces Color / contrast curves that are applied to raw footage in order to make it look “correct” on various viewing devices such as computer monitors and TV screens Lut’s Adapt the color information to fit predefined specifications Color grading = altering and enhancing the color of a picture The pipeline Consists of the processes and people that work together to bring breathtaking scenes and characters to life for film, TV and games Kickoff your pipeline 1. Create a breakdown of assets, sequences, shots 2. Create a task template for your sequences, shots, assets 3. Create a list of all tasks and statuses, so you can track what needs to be done and what’s completed 4. Define naming convention and folder structure 5. Scripts & automate with python The benefits By using a good pipeline, a lot of time is saved, which can be used to create the best possible version of a project The people Fear of failure, Fear of separation and fear of change Need to work together and help each other