Debayering and RAW Image Data
Debayer: The process of converting raw image data captured from a camera sensor into an RGB image.
Raw Data: Signals sent straight from the sensor before debayering, allowing more flexibility in post-production.
Raw Footage: Raw footage is transformed into RGB video, where signals for each color channel (red, green, blue) are recorded individually.
Video Recording and Compression
Component Video: A form of video that uses:
Luminance signal (greyscale)
Two chrominance signals (color)
Records these components separately.
Color Space: The range of hues and tones a system can reproduce.
External Video Recorders: Dedicated devices that record camera signals and have built-in monitors, but are not cameras.
Compression: The process of reducing video/audio into smaller packages for storage, which can be decompressed while retaining original quality.
Codecs: Compression schemes used to maximize picture quality for recording versus minimizing data size for playback.
Audio Recording
External Sound Recorders: Commonly used in video productions to record audio separately from the camera’s footage.
Film Cameras
Functionality: Film cameras focus light onto a rectangular area of film.
Operation:
Shutter blocks light; after exposure, film is pulled into position.
Shutter reopens to allow light in for the next frame.
Film Projectors
Similar to cameras, but project developed images onto screens using bright lamps behind frames.
Film Types and Evolution
Early Film: Made from highly flammable cellulose nitrate (35mm wide).
Cellulose Acetate: More stable and replaced the initial film types; polyester has since taken over.
Larger film size correlates with increased quality.
Film Processing: Using larger areas of emulsion per exposure decreases grain and imperfections in the image.
Professional Film Stock
Color Negative Film: Used in most professional productions; tonality and colors reversed upon development.
Editing Film: Films shot on film can be digitized through video/digital transfer or digital intermediate processes.
Super 8mm Film History
Introduction: 8mm introduced in 1932, later super 8 with larger frames in 1965, aspect ratio 1.33.
16mm Film History
Introduction: 16mm introduced in the 1920s, with a 1.33 aspect ratio.
Super 16: Developed in the 1970s to capture a larger image with a 1.67 aspect ratio.
35mm Film and Features
Usage: Hefty cameras, used in high-budget productions.
Allows for various aspect ratios including standard 1.33 ratios with perforations for soundtracks.
Super 35mm: Utilizes sound area for image capture, facilitating 1.85 or 1.78 (16:9) aspect ratios.
Larger Film Formats and Projection
65mm Film: High-budget films photographed in 65mm shown on 70mm prints with added sound width.
IMAX and Omnimax: 65mm also utilized in these formats, running horizontally through the camera.
Film Camera Components
Lens: Focuses light onto film.
Lens Mount: Connects the lens to the camera body.
Viewfinder: Allows for previewing the shot via a reflex system.
Film Chamber: Holds the film before and after exposure.
Motor: Powers the film movement for exposure.
Claw: Pulls down the film frame by frame during use.
Film Gate: Area where raw stock is exposed to light, held flat by pressure and aperture plates.
Shutter: Closes between exposures to block light,
Shutter Speed and Exposure: Duration the shutter remains open determines exposure intensity.
Stock and Film Characteristics
Raw Stock: Unexposed film, moves through a feed reel into the film gate.
Shutter Types: A variable shutter can adjust the shutter angle, altering speed and exposure.
Standard Speed and Frame Rates
Standard Projection Speed: 24 fps.
NTSC Frame Rates: 23.98 fps for telecine transfers to match video camera rates.
Film Handling and Video Assist Technology
Magazines: Detachable chambers for film loading.
Video Assist: Tracks footage using an additional video camera.
Sound Dampening Techniques
Barney Covers: Used to quieten high-end film cameras and protect from temperature changes.
Multi-Format Cameras & Lens Adjustments
Multi-Format Cameras: Some can shoot in 16mm and super 16, requiring lens adjustment to fit different formats.
Parts of Film and Development Process
Emulsion Layers: Consist of light-sensitive silver halide crystals in gelatin atop a film base, covered by antihalation backing to minimize scattered light reflection.
Development: Light exposure creates latent images, revealed through chemical reactions reducing silver halide to metallic silver, forming the film: darkness correlates with concentration of silver.
Negative-Positive Process
Function: Printing from the negative involves inverting colors again to produce a positive image, typically standard for 16mm and 35mm filmmaking.
Reversal Film Process
Outcome: Yields a positive image projected directly, previously standard in 8mm and 16mm. Relies on unexposed silver halide removal and additional exposure to establish brightness values during processing.
Characteristic Curve Analysis
Graphical Representation: Shows exposure versus density relationship, indicating how exposure affects film density through progressive light exposure.
Negative Stocks: More exposure = more density.
Positive Stocks: More exposure = less density (inverse).
Film Speed and ISO Considerations
Film Speed: Reflects light sensitivity; faster stocks need less light for exposure.
Exposure Index (EI): A numerical representation of speed useful for calculating optimal exposure.
ISO Number: Commonly recommended by manufacturers; medium speed is approximately ISO 100.
Doubling ISO: Increases light sensitivity by double.
Film vs Digital ISO Differences
Film ISO remains fixed due to the properties of the physical film.
Digital ISO adjusts sensor sensitivity via electronic amplification of captured light.
Color Temperature and Film Stocks
Balance: Film types are made for specific color temperatures:
Tungsten film: Balanced for 3200K.
Daylight film: Balanced for approximately 5500K.
Contrast and Gamma Relations
Characteristic Curve Steepness: Indicates film's contrast level; steeper curves indicate higher contrast.
Gamma: Measures this steepness within a specific range.
Force Processing: Raising ISO sensitivity through development processes.
Reducing Gamma Effects
Pulling (underdeveloping) or flashing (exposing to slight light prior) decreases contrast with minimal bright area impact.
Bleach Bypass: Skips crucial bleaching steps, resulting in metallic silver remaining in emulsion, affecting colors and contrast.
Depth of Field Characteristics
Depth of Field (DOF): Extends from in front of and behind the subject centered in focus.
Control Mechanisms: Adjust camera distance, focal length, or f-stop to manipulate DOF.
Hyperfocal Distance: Closest point resulting in optimal DOF.
Lens Types and Functions
Normal Lens: Medium focal length, yielding a natural perspective, often considered 50mm in photography (narrow angle in cinema).
Focal Length Effects: Determines field of view and how closely a subject appears.
Aperture and Exposure Adjustments
F-Number Calculation: Aperture size determined by focal length over the aperture diameter. Common scale: 1, 1.4, 2, 2.8, 4… 32.
T-stop: Compensates for light loss due to reflections and scatter.
Lighting Techniques and Equipment
Light Types: Differentiated by characteristics such as hardness or softness (clean harsh shadows vs diffuse light).
Three-Point Lighting Setup:
Key Light: Highest intensity light defining key shadows.
Fill Light: Softens shadows without causing new ones.
Backlight: Situates behind the subject, enhancing dimensions.
Electrical Load and Contrast
Outlet Power Safety: Common American outlets provide 15 amps; exceeding this can lead to electrical fires.
Contrast: Critical element conveying information and emotions, defined through scene choices and image capture intricacies.
Video Signal and Gamma Transfer Curves
Video Systems: Compression applied to tones; digital systems manage a wide brightness range effectively.
Characteristic Curve: Similar to film, indicative of exposure versus density, necessary for effective transition from scene to display.
Density Levels and Curve Dynamics
D-min: Minimum density established even without exposure. It has video equivalents considering digital noise.
Straight Line Section: Constant change in density; includes toe and shoulder curves to determine density consistency at extremes.
Film Processing and Gamma Impact on Color Grading
Gamma Applied during Grading: Affects how images appear on various monitors and how exposure adjustments influence final output.
Deciding Impacts on Exposure: Best practices using observations such as zebra indicators, histogram analysis, and waveform monitor adjustments ensure accurate results.
Conclusion and Practical Application
Manual Settings: Always set ISO, shutter speed, and iris manually based on scene requirements and tonal highlights/shadow preservation. Adjust smoothly between shooting, monitoring, and post-production stages.