Thursday, October 24, 2013
Saturday, October 19, 2013
Digital Cameras Informations : A digital camera is a camera that stores pictures on a memory card instead of film. Because of this, a digital camera can hold many more pictures than the traditional film camera. A digital camera can sometimes hold hundreds of pictures. Different size memory cards are sold, that can hold more or fewer pictures. Most digital cameras can use a USB cable that connects into a computer to take the pictures that are in the camera and send them to the computer. Digital photography is a kind of photography where a digital camera is used to take photos. Digital cameras use an image sensor instead of photographic film, based on chemicals. Very often, they also use a memory card to store the photos in a digital format. Most photography is digital, though some photographers still use the old film cameras. The majority of cameras are part of a mobile phone, called a "camera phone". They can send their pictures to other phones and other devices. Most camera phones do not make as good pictures as larger separate cameras do, especially where light is not bright. Most digital cameras can serve as Video cameras. Some have a direct link to another computer where the data may be stored. Digital and film cameras share an optical system, typically using a lens with a variable diaphragm to focus light onto an image pickup device. The diaphragm and shutter admit the correct amount of light to the imager, just as with film but the image pickup device is electronic rather than chemical. However, unlike film cameras, digital cameras can display images on a screen immediately after being recorded, and store and delete images from memory. Many digital cameras can also record moving video with sound. Some digital cameras can crop and stitch pictures and perform other elementary image editing.
Thursday, October 17, 2013
Eye-controlled focusing: Through the tracking of eyeball movements, EOS cameras equipped with eye-controlled focusing (ECF) are able to choose the appropriate autofocus point based on where the user is looking in the viewfinder frame. ECF comes especially useful in sports photography where the subject may shift its position in the frame rapidly.
Quick control dial: Most prosumer and professional level EOS cameras feature a large quick control dial (QCD) on the camera back. Allowing easy operation of the camera using the thumb, the QCD is used for quick access to often-used functions that may otherwise require a more complicated procedure of button-presses and dial-clicks
Multi-point autofocus system: Currently, top-line EOS cameras have 61 autofocus (AF) points, the most in their class. Two Canon cameras have this system—the EOS 5D Mark III, on sale since March 2012, and the EOS-1D X, announced in October 2011 and originally scheduled for sale in April 2012, but delayed until June 2012. The release of the 5D MkIII gave Canon the lead once again in this category; previously, its top-line cameras had 45 AF points, which led the industry until Nikon released its D3 and D300 DSLRs with 51-point AF systems. A higher number of AF points increases the chances of a sharply-focused photograph in situations where the subject travels across the frame at high speeds (e.g., sports, birds). The number, type, features and performance of autofocus point array systems is likely to continue to evolve.