Pixels and Image Size
One of the hardest thing for people to understand about digital photography is how the number of pixels in an image affects how it is displayed and printed.
In this short clearly written book we discuss all aspects of this relationship using text, animations and Excel worksheets. This guide is available as a 32 page full-color, fully searchable PDF eBook you can download instantly.
Digital images are formed from tiny dots of color. The dots, usually many millions per image, are so small and close together they blend into the smooth continuous tones we're so familiar with from film. These images are captured directly with digital cameras, or by scanning a transparency, negative, or print. The end result is an image in a universally recognized format that can be easily manipulated, distributed, and used. However, just because photography is an art form, it doesn't mean you don't
have to know some math. When it comes to displaying or printing your images, this section could be titled "So You Have to Know Arithmetic After All." If your camera captures an image that's 3648 x 2736 pixels in size, what does that mean when you e-mail it, post it to a Web site, or make a print? In this section you find out how to answer these kinds of questions.
The calculations we'll be using in this book are nothing more than subtraction, addition, multiplication and division-subjects you mastered early in school. However, to make it easier to explore the various relationships being discussed, you can use the Excel worksheet "Pixels & Images Calculator" downloadable at the link below or by clicking the Excel button in this section:
The worksheet, named pixelcalc.xls, has been saved in Excel 5 format so that version and all later versions of Excel can read it.
ShortCourses and PhotoCourse Publishing Programs ...2
Image Sensors-Introduction ...5
Types of Image Sensors ...6
Image Sensors and Pixels ...7
Image Sensors and Image Size ...9
Exploring Images Sizes ...13
Image Sensor Sizes ...14
Aspect ratios ...15
Exploring Aspect Ratios ...17
Image Sensor Sensitivity and Noise ...18
Image Sensors and Color ...19
Cleaning Image Sensors ...22
Pixels and Screen Display ...23
Exploring Pixels on the Screen ...25
Pixels and Print Sizes ...26
Exploring Print Sizes ...27
Pixels per Inch ...28
Exploring Pixels Per Inch ...30
Pixels and Colors ...31
Exploring Pixels and Colors ...32
Scanning and Image Sizes ...33