This document provides an overview of key photography concepts including pixels, megapixels, resolution, color modes, histograms, and preparing images for print in Photoshop. It defines pixels and megapixels, explains how to calculate megapixels from image dimensions. It also outlines the differences between screen and print resolution, RGB and CMYK color modes, and how histograms can be used to analyze image exposure. The goal is for the learner to understand these essential digital photography and editing fundamentals.

1. Digital Darkroom
Visual Arts: Photography • Sargento • AWQ3M/4M

2. Learning Goals
Today I will learn…
š Pixels & Megapixels
š Resolution
š Colour modes
š Adobe Photoshop:
š Workspace
š Basic tools
š Histogram
š Adjustments & Adjustment Layers

3. Recap
š Q: What is a pixel?
š A: The smallest editable component of
an image/display. A pixel can only
display one colour.

4. Recap
š Q: What is a megapixel?
š A: A megapixel is a measurement of
pixels by the millions
š 1 megapixel = 1 million pixels

5. Recap
š You can calculate a megapixel
by multiplying the image’s
width and height in pixels;
š For example;
š 4752 px wide X 3168 px high =
15,054,336 pixels or
15 megapixels

6. Resolution
š Image resolution is the detail an image holds
š Higher resolution means more image detail.
š Image resolution can be measured in various ways;
š DPI = dots per inch (measurement when referencing print files)
š PPI = pixels per inch (measurement when referencing digital files)
š Width x Height in pixels (1920 px x 1080 px = HD resolution)

7. Resolution

8. Resolution
Web/Screen
Resolution = 72 DPI/PPI
Print
Resolution = 300 DPI/PPI

9. Colour Modes
š When creating graphics, editing photographs, etc. for
different purposes, along with resolution, you need to
consider which colour mode you will be working in.

10. Colour Modes
RGB CMYK

11. Colour Modes
RGB CMYK
š Red, Green, Blue
š Created with light
š Use for web/screen
š Start with black and add
amounts of light (RGB)
š Cyan, Magenta, Yellow,
Key (Black)
š Created with ink
š Use for print
š Start with white and add
amounts of ink (CMYK)

12. Adobe Photoshop

13. Histogram
š Histogram displays information
regarding your photograph;
š Shadows (blacks)
š Midtones (greys)
š Highlights (whites)

14. Histogram
Amount
of
Pixels

15. Histogram
š Histogram will allow to analyze your
photograph’s information to ensure
you have a properly exposed image

16. Underexposed Correct Exposure Overexposed

17. Histogram
Underexposed
Most of the information is
towards the shadows (blacks)

18. Histogram
Overexposed
Most of the highlight (white)
information is on the right of
the histogram.

19. Histogram
Correctly exposed
Distribution of shadows,
midtones, and highlights.
Nothing is “climbing” on either
side.

20. Setting Up for Print
š Let’s setup your photographs for printing…