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Units of Measurement. 2.01 Understand Digital Raster Graphics. What Unit of Measurement to Use. Quiz Question: List as many units of measurement that you can think of as a class. Did you have more than one from the list below?. Inches Pixels Points Picas.
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Units of Measurement 2.01 Understand Digital Raster Graphics
What Unit of Measurement to Use Quiz Question: List as many units of measurement that you can think of as a class. Did you have more than one from the list below? • Inches • Pixels • Points • Picas We generally pick what we are comfortable with, but in Graphic Design it should be based on need.
Inches • The standard unit of measurement for the United States and U.S. standard sized papers. • What is 8.5” x 11” called? 11” x 14”? 11” x 17”? • Letter, Legal, and Tabloid • Letter size is standard for most printers, resumes, and other common documents. • Works well when defining document sizes for print. • What most of us are comfortable with.
Pixels • The most common unit of measurement for computer screen display. • Generally represented by one dot that is illuminated on a computer screen. • Many pixels make up an image or images. • A precise measurement system for web-design. • Lacks flexibility as screen sizes change.
Points • The standard unit of measurement for typefaces. • 1 point represents 1/72 of an inch. • Therefore text formatted with a font size of 72 pt is about one inch. • However, variations occur due to font designs. • Standard size for print paragraphs = 12 pt (Generally)
Picas • Quiz time: What is 11 inches divided by 3? • Quiz time, part two: What is 72 divided by 3? • One pica equals 1/6 of an inch. Six picas per inch. • Often used in print design, since it is easily divisible. • Picas work well when applying the Rule of Thirds.
Begin with the End • When talking about image resolution and color mode to choose when designing, you have to think about what the desired output will be. • Web? Or Print?
What is resolution? • Resolution is a measure of the amount of detail that is stored in a digital image. • Higher resolution means higher quality. • But is high resolution always a good thing. • Lower resolution means lower quality. • But is lower resolution always a bad thing.
Image Resolution • Resolution is measured in PPI, or pixels per inch (the number of pixels contained in one inch). • The higher the PPI, the better the quality. • The higher the PPI, the larger the file size. • Image editing software can be used to change the resolution of an image.
Image Output Methods • Images can be viewed in two ways • On a screen or monitor or by printing it on paper • Monitors • Monitors are low resolution devices, most display 72 ppi. • Additional image resolution will increase file size, without affecting display quality. • Printers • The resolution at which printers can print is measured in Dots Per Inch (DPI). • Printers are high resolution devices and require high resolution images in order to print images clearly without pixelation or blurriness.
Match The Image Quality To The Delivery Method • Images that will be displayed on a monitor do not need a high resolution. • Using a low resolution means smaller file sizes. • Images with small file sizes load quicker. • Images that will be printed need a higher resolution. • Images with 300 PPI are better for printing on more sophisticated printers and will produce higher-quality photographs.
What About Color Mode? • Color Modes: a mathematical model that describes the way colors can be represented as numbers or percentages, typically with three or four values. • There are many types of color modes, but generally you will work with two when editing raster images. • RGB Color • CMYK Color
RGB Color • RGB: assigns an intensity value to each pixel ranging from 0 to 255 for each of the red, green, and blue components in an image. • If all RGB values are 0, you get black. • If all RGB values are 255, you get white. • On-screen display is represented by RGB, therefore RGB color is best used for images that will be displayed on a monitor or webpage.
CMYK Color • CMYK: assigns a percentage value for each of the process inks. Cyan, magenta, yellow, and black. • If all percentages are set to 0, the result is white. If all percentages are set to 100, the result is black. • An image should be converted to CMYK before exporting for images that will be sent to print.
Quiz Time • An image is being designed that will be display on the new company website. What color mode and what resolution should the image have? • RGB color and 72 ppi. • A poster is being created that will have 500 copies printed to promote the upcoming concert. What color mode and resolution? • CMYK color and 300 ppi.