Digital Photography For Dummies

From Digital Photography For Dummies, 6th Edition by Julie Adair King, Serge Timacheff

To take quality photos on a digital camera you need the correct resolution, format, and ISO setting. Most digital cameras display common symbols for exposure modes and offer basic file formats for creating and saving your digital photos.

Resolution in Digital Photos

The number of pixels (picture elements) in your digital photo is managed by resolution. If you don't have enough pixels per inch (ppi) in your image it will appear blurry. Here is the minimum pixel count your need for quality photos:

Print Size	Pixel Count	Megapixels
4 x 6	800 x 1200	1
5 x 7	1000 x 1400	1.5
8 x 10	1600 x 2000	3
11 x 14	2200 x 2800	6

*Based on 200 ppi; 1 megapixel = 1 million pixels

Format of a Digital Photo

Format is the way your camera records and stores the data that make-up a digital photo. Camera Raw, or a high-quality JPEG formats, which usually come standard on digital cameras, are your best bet for a clear image. A low quality JPEG can result in a blocky, defected image like this one:

The ISO Setting on Your Digital Camera

The ISO (International Standards Organization) setting on your digital camera controls how sensitive the image sensor is to light. The higher the ISO the less light you need to capture a photo. Beware: an ISO set too high may cause an image with noise, or a speckled defect.

Exposure Modes on Your Digital Camera

Most digital cameras offer you a choice of exposure modes. Here are common symbols on a digital camera menu or mode dial that represent exposure modes:

What It Looks Like	What It Does
AUTO	Automatic mode; camera selects exposure settings appropriate for most subjects
	Manual exposure mode; user sets aperture (f-stop) and shutter speed
	Aperture-priority autoexposure; user controls aperture, camera sets shutter speed
	Shutter-priority autoexposure; user controls shutter speed, camera sets aperture
	Portrait scene mode; automatically chooses settings most appropriate for portraits
	Action scene mode; automatically chooses settings designed to capture moving subjects
	Landscape scene mode; chooses settings appropriate for landscape photography
	Macro mode; chooses settings appropriate for close-up shots

File Format Guide for Your Digital Photos

When you take and store a digital image you need to choose a file type, or format. Here are the popular choices when you choose a format for your digital photo:

Format	Description
Camera Raw	A format offered by some digital cameras. Stores raw, “uncooked” data from the image sensor, without applying normal adjustments to sharpness, color, and exposure. Gives photographers ultimate control over images and editing flexibility, but files must be converted to a standard format before sharing online, printing, or viewing in most photo programs.
JPEG	The most popular digital photography image format. JPEG compresses images to make files significantly smaller, but too much compression reduces image quality. Used for print, the Web, and e-mail.
TIFF	The leading format for files that will be used in print publications such as newsletters and magazines. Preserves all image data but usually results in larger file sizes than JPEG and can’t be displayed by Web browsers and e-mail programs. The best format for storing converted RAW files and for edited JPEG files.