Presentation on theme: "Chapter 10 Digital Imaging: Capture. Digital imaging – electronically producing, viewing, or reproducing an image Pixel – a square with a uniform brightness."— Presentation transcript:
Digital imaging – electronically producing, viewing, or reproducing an image Pixel – a square with a uniform brightness and color. Sometimes called a pic ture el ement. Resolution – number of pixels per unit of length Image size – physical size of a photo
To understand digital imaging, compare it with conventional photography. First an image must be digitized. For computer use, this image is converted to digital form using CMOS or CCDs (charge-coupled devices). Each position on the grid is recorded as a pixel.
The amount of information in a digital image – and therefore its technical quality- is determined by both the number of pixels and the number of possible values each pixel can hold. The finer the resolution, the larger the number of pixels needed. Without adding more pixels, increasing the image size, decreases the resolution.
Display allows you to see instant results of each shot Advantages You get to select ISO rating for each shot Allows you to review your images before developing Zoom Lenses OPTICAL DIGITAL Magnifies the entire scene Higher image quality Only enlarges pixels Lower image quality Using a Digital Camera Make sure you always have fresh batteries Never insert or remove your memory card while your camera is on! Select the file type - jpg
There are many types of cameras so it’s important to find one that you like, understand, and meets your needs Keep in mind the following factors when making your final decision -Lens choice: some have interchangeable lenses others have fixed lenses. -Image quality: the greater the resolution the better quality your image will be. Test out cameras to make sure they meet your needs. -Flash: built in flashes are useful but limited. Look into external flash units to improve control and expand your options. -Types of memory: Memory cards store images until you can transfer them to a computer. The more memory you have, the more images you can take and store at once. Storage space on memory cards varies greatly so make sure you get one that will meet all you needs.
Histograms show the brightness values of all the pixels in an image On a digital camera you will find a histogram used as kind of a digital light meter In scanning software and photo editing programs, the histogram guides your lightness and contrast adjustment tools
Gamut is the entire range of colors. The gamut of our eyes (all the colors we see) is much greater than the gamut that can be printed. Digital imaging reproduces all the colors in the spectrum by using the three primary colors: red, green, and blue. There are 256 color tones that can be used in printing.
As soon as you create a digital image, you have to think about storing it. Most digital cameras use removable memory cards for storage. Computers store images on their hard drives in binary form using a combination of 1’s and 0’s. Adding additional external hard drives is a popular option for storing large numbers of photo files. Most computers come with CD or CD/DVD recorders (or burners) that allow you to store images on disks. These will start to deteriorate in time.
PSD TIFF RAW JPEG Adobe’s proprietary format for saving Photoshop documents. Images can be opened ONLY in Photoshop for editing. Compresses photos by discarding pixels determined to be unnecessary. Repeated saving degrades the image. Most universal format for high quality photographs and can be opened on any computer by nearly every program that works with photographs. Files are like exposed but undeveloped film. The files are unprocessed and left just as the camera recorded them.