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Digital photography All-in-one desk reference 3rd edition - Busch D.

Busch D. Digital photography All-in-one desk reference 3rd edition - Wiley publishing, 2006. - 755 p.
ISBN: 0-470-03743-1
Download (direct link): digitalphotographyallinone2006.pdf
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? An optical viewfinder, which you can peer through to frame and compose your image. Some digital cameras with large LCDs donít have optical viewfinders at all.
Some cameras have two LCDs: one on the back in the traditional location, and a second one inside the camera and visible through an optical system.
Choosing Your View 101
This variety is an electronic viewfinder or EVF. None of these are ideal for every type of picture-taking application.
LCD viewfinders
In a non-SLR, the liquid crystal display, usually measuring 1.5-2.5 inches diagonally, shows an electronic image of the scene as viewed by the sensor.
(Digital SLRs canít preview images on their LCD because the mirror, shutter, and other components get in the way of the sensor until the moment of exposure.) On the one hand, thatís good because you can view more or less the exact image that will be captured. Itís also not so good because the LCD screen is likely to be difficult to view, washed out by surrounding light, and so small that it doesnít really show what you need to see. Moreover, the backlit LCD eats up battery power. Iíve used digital cameras that died after 20 minutes when the LCD had depleted their rechargeable batteries. Luckily, 0
some digital cameras let you specify that the LCD is turned on only when ^
composing a picture or only for a few seconds after a picture is taken (so Ó i
that you can quickly review the shot). 3 <n
Although often not usable in bright daylight, LCDs, such as the one shown in Figure 1-9, are better in more dimly lit conditions. Some third parties offer LCD hoods that fit over the back panel of the camera to shield the LCD from direct illumination. If you mount your camera on a tripod and make sure all the light is directed on your subject, an LCD is entirely practical for framing, focusing, and evaluating a digital image (even outdoors, if you use one of those protective hoods).
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Figure 1-9: LCD screens work fine in dim light.
102 Choosing Your View
As you shop for a digital camera, check out the LCD under a variety of conditions to make sure it passes muster. Here are some things to look for:
? Brightness controls: Many cameras include a brightness control that allows you to increase the brightness of the LCD to make it easier to view in full sunlight, or to decrease the brightness indoors to use less battery juice. A related factor is whether the LCD automatically ďgains upĒ by amplifying a dim image to provide a usable view when itís very dark.
? Swivel mount: The LCD doesnít have to remain fixed rigidly to the back of the camera. Some swivel and rotate, allowing you to point the camera in one direction and move the LCD so that you can easily view it at an angle. (Alternatively, the part of the camera with the lens can swivel while the part with the LCD remains in place.)
? Resolution and size: Ultracompact digital cameras often have tiny LCD displays, on the order of 134 inches (measured diagonally), and others have more generous 2.5-inch LCDs. The size of the LCD and the number of pixels it contains will partially determine how easy it is to preview your image. Some may have as few as 80,000 pixels; others may have 230,000 pixels or more. Guess which is easier to view!
? Display rate: Some digital cameras update their LCD images more efficiently, so the view is smooth even when the camera or your subject is moving. Others offer up blurry images or ghost trails that make it difficult to view images in motion.
? Vanishing images: What happens when you press the shutter release? Does the image instantly freeze as soon as you start to press the button but before you actually take the picture? If so, what you saw might not be what you get because your subject matter might have changed in the time between the initial press and the actual photo. Or, does the LCD go completely blank, leaving you with no clue about what youíre shooting? Ideally, the LCD should display a real-time image right up until the instant before the picture is taken.
? Accurate viewpoint: Believe it or not, even though an LCD viewfinderís display is derived from the same sensor used to make the exposure, the LCD might not display 100 percent of the sensorís view. Instead, it might trim a little off the sides, top, and bottom, and show you 80 to 90 percent of the actual picture. Thatís not good when youíre carefully composing a photo to make the most of your pixels, particularly with lower-resolution cameras that donít have pixels to spare.
? Real-time corrections: Some cameras have live histograms ó graphs that show the distribution of the tones in the image ó that can be viewed on the LCD and used to correct exposure manually while you shoot. These are all non-SLR types, of course. With a dSLR, a histogram is visible only after the exposure.
Choosing Your View 103
? Accurate rendition: Iíve found that some LCDs donít let you evaluate just how good (or bad) your picture is because they provide an image thatís more contrasty, or brighter, or with more muted colors than the actual digital picture. You donít want to reshoot a picture because you think it looked bad on the LCD, or worse, make a manual exposure or other adjustment to correct a defect that appears only on the LCD and not in the finished photo.
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