Digital Photography Russell Taylor
Digital Cameras • Digital photography has many advantages over traditional film photography. Digital photos are convenient, allow you to see the results instantly, don't require the costs of film and developing, and are suitable for software editing and uploading to the Internet. • The basic attribute of a digital camera that determines image quality is its megapixel rating. This number refers to the amount of information that the camera sensor can capture in a single photograph. • Cameras with high megapixel ratings take larger pictures with more detail. Those photos will also look better when printed, especially in bigger sizes.
Megapixels! • At five megapixels, image quality gets near to that of analogue film. If you're willing to spend about £100 on a digital camera, then it's difficult to find a model that doesn't have five megapixels. These cameras are fine for most people who just want to take a few family snapshots or capture holiday memories. • The more you spend, the more megapixels you get. In the £300 to £500 range, you can expect to find cameras with anywhere from 10 to 14 megapixels. • If you plan to take serious artistic photos, sell prints of your photos, or post large, high-resolution photos on the Internet, this is the range for you. • If you think you need a more powerful camera than that, you probably don't need to be doing this course!
Features • There are also many additional features available on digital cameras, • including image stabilization, • on-board image editing, • colour correction functions, • auto-bracketing and burst modes. • A lot of these can be handled by image editing software, and so they can be unnecessary (and often inferior) when built into a camera. Burst mode, macro mode and image stabilization are probably the most useful extra features.
Settings – Getting Them Right! • Auto mode – great for snapshots! • Learning settings gives you CONTROL! • When you're changing the settings on a camera, you're trying to find the proper exposure for the subject and lighting conditions. • Exposure is the amount of light hitting the camera's sensor when you take a photo. Generally, you will want the exposure set so that the image captured by the camera's sensor closely matches what you see with your eyes. • The camera tries to accomplish this when it's on full automatic mode, but the camera is easily fooled and a little slow, which is why manual settings usually produce better pictures.
Controlling Exposure • To adjust exposure, you can tweak two different settings: aperture and shutter speed. • Aperture is the diameter of the lens opening - a wider aperture means more light gets through. • Aperture is measured in f-stops. • Higher f-stop numbers mean a smaller aperture. • The aperture setting also affects depth of field, the amount of the photograph that is in focus. • Smaller apertures (higher f-stops) give longer depth of field. • A person in the foreground and the cars 20 feet behind her could all be in focus with a small enough aperture. A larger aperture results in a shallow depth of field, which you normally use for close-up shots and portraits. http://www.cambridgeincolour.com/tutorials/depth-of-field.htm
Shutter Speed • Shutter speed is the amount of time the shutter remains open to allow light through it. • An extremely fast shutter speed is 1/2000 of a second, while camera settings usually allow up to about one second, which is very slow. • One-sixtieth of a second is about as slow a shutter speed as you can use when taking a hand-held shot, and not get any blur. • Some photographers force their camera shutters to stay open for much longer to create various special effects. For example leaving a camera pointed at the night sky with the shutter open for several hours results in a photo of the paths the stars seem to take across the sky as the Earth rotates.
Practice and Experience • Practice and experience are the best ways to figure out which combinations of aperture and shutter speed are best for different kinds of photos. • While a slow shutter speed lets in more light, it also makes it very difficult to get a crisp picture. Any movement at all (of either the subject or the camera) will result in blurring. • Sometimes you might want this effect, but for a clear photo of a moving object, you need a fast shutter speed
Semi-automatic Modes • Many cameras have a semi-automatic mode that can be set to either aperture priority or shutter priority. • You can either set the aperture or shutter speed (depending on which priority mode is enabled) to the desired setting, and the camera calculates the right settings to accommodate the lighting conditions. • The camera might also have a variety of modes to choose from, such as sports mode or outdoor mode. These are aperture/shutter speed presets. • There is no substitute for experience!
Taking Good Photographs • Set your focus ahead of time. When using auto focus, pressing the shutter release halfway tells the camera to focus in on your target. You might have to wait for a few seconds with that button halfway down, but when you finally take the picture, the camera won't have to waste time focusing. • Use manual exposure settings. It takes time for the camera to calculate exposure settings in full automatic mode, so set them manually whenever you can. • Don't use flash unless it's absolutely necessary. The time it takes to charge the flash can create additional lag. If you need a flash, consider using an external flash unit. • Use the viewfinder instead of the LCD screen. This will save your batteries and reduce the amount of work the camera has to do.
Taking Good Photographs (2) • Reduce image quality.Digital cameras allow you to adjust the size and resolution of the photos you are taking. Huge, uncompressed Tiff files will look great, but they might create lag. • For action shots, try a lower quality setting with smaller images. Obviously you're sacrificing large, high-resolution images, but it will increase your chance of getting the shot you wanted. • Experiment with your camera's settings to find the right balance between image quality and shutter lag. • Use burst mode.If your camera offers it, burst mode is a great way to get the precise moment you're shooting for by taking a series of quick photos over the course of a few seconds. • Depending on the camera, burst mode (or continuous mode) may require a compromise in image quality.