Enhancements and Colour Management Flashcards
Under what conditions will auto white balance not work?
Forensic light source (direct sunshine)
Studio lights (incandescent white balance)
What happens when you select different channels in photoshop?
The selected channel will allow their own colour to pass while blocking other colours. Therefore, channels will lighten their own colour while darkening their complement (when in RGB mode).
What is a colour model?
A mathematical representation of colour values which give a set of colours.
What are the properties of the RGB colour model?
Additive model
Primary colours red, green, and blue
Transmits light through filters
Mixed to create other colours
All three colours make white
Camera captures in RGB
What are the properties of the CYMK colour model?
Subtractive colours
Reflected light
Cyan, Magenta, Yellow, and Key (black)
Used in printing
Mixing results in black.
What are the three tonal ranges in an image and how they be adjusted for use in forensic photography?
Highlights, Midtones, and Shadows
Images of fingerprints and other physical evidence is usually in grayscale. Can use levels and curves to extract more information out of an image by spreading the tonal range.
