Transcript Slide 1
Camera Introduction Presented by Shaughan Digital Cameras • 2 Main Types – Compact (Point & Shoot) – Digital Single Lens Reflex (DSLR) Digital Cameras • Compact (Point & Shoot) Digital Cameras • Digital Single Lens Reflex (DSLR) Digital Cameras Digital Cameras Digital Cameras Sensor Camera Control ?? Auto or Manual ?? Camera Control Auto • Focus. – Cameras have one or more focus zones or areas, each of which is often indicated in the viewfinder with cross hairs, boxes or brackets. • Exposure – Programmed auto exposure measures light reflecting from the scene and uses these readings to set the best possible exposure. Camera Control Auto • Focus. – Cameras have one or more focus zones or areas, each of which is often indicated in the viewfinder with cross hairs, boxes or brackets. • Exposure, White Balance, Shutter Speed, ISO, Aperture & Flash – All controlled by the camera. Camera Control Auto • White Balance – The colour cast in a photograph is affected by the colour of the light illuminating the scene. Adjusts colour balance to make white objects in the scene look white in the photo. • Flash – If the light is too dim, the auto exposure system will fire the camera's built-in flash to illuminate the scene. Camera Control Auto • Program Mode – Pre programmed for a variety of situations such as portrait, landscape, or sports. • Aperture Priority – – Select the aperture (F stop or lens opening) needed to obtain the depth of field you want and the exposure system automatically sets the shutter speed to give you a good exposure. Camera Control Auto • Shutter Priority – – lets you choose the shutter speed you need to freeze or deliberately blur camera or subject movement and the camera automatically sets the aperture to give you a good exposure. Camera Control • Manual Mode – – Gives the greatest control over your images Camera Control • Shutter (Speed) – eg. 1/1000, 1/125, 1/15, 1/2, and 1 second • Controls Light and Motion • The shutter keeps light out of the camera except during an exposure, the length of time the shutter is open affects both the exposure of the image and how motion is portrayed in it. Camera Control • Shutter and exposure – – Faster shutter speeds let less light strike the image sensor making the image darker. – Slower shutter speeds let more light in making an image lighter. Camera Control • Shutter and motion – – The longer the shutter is open, the more a moving subject will be blurred in the picture Aperture Aperture Aperture & DOF Aperture & DOF • Here a large aperture kept the foreground sharp but softened the background. Aperture & DOF • Here a small aperture kept both the foreground and background sharp. Aperture & DOF Shallow Greater Aperture & Lens (Speed) F1.2 F3.5 – F6.3 Choosing Image Quality and Size • The size of an image file and the quality of the picture it contains depend in part on the number of pixels in the image and the amount of compression used to store it. Choosing Image Quality and Size • Compression – – To make large image files smaller. Format called JPEG and allows you to specify how much they are compressed. – Less compression, sometimes called Fine mode, gives you better images so you can make larger prints, but you can't store as many images. Choosing Image Quality and Size • Other Formats – – TIFF • Can be used as is in most image editors • Large file size – RAW • Camera specific • Similar to film before ‘processing’ • Ability to manipulate settings after the shot is taken Choosing Image Quality and Size • Image size – In addition to offering compression modes, many cameras let you also change image size eg. – 640 x 480 or – 1600 x 1200 Choosing Image Quality and Size • Image size – In addition to offering compression modes, many cameras let you also change image size eg. – 640 x 480 or – 1600 x 1200 Choosing Image Quality and Size • Enlargement & Compression - Metering • All parts of a scene are usually not equally important when determining the best exposure to use. • In a landscape, for instance, the exposure of the foreground is usually more important than the exposure of the sky. Metering • Matrix – – metering divides the image area into a grid and compares the measurements against a library of typical compositions to select the best possible exposure for the scene. Metering • Center-weighted – – meters the entire scene but assigns the most importance to the center quarter of the frame where the most important objects usually are located. Metering • Spot – – evaluates only the area within a small area in the middle of the viewfinder. – This mode is ideal when photographing a subject against a bright or dark background. Metering • Conclusion – Matrix / Multi-segment metering mode is the best choice for most forms of photography. – Spot metering mode is more than likely to offer better quality photographs in highcontrast lighting conditions. Focus • Single (or one) area focus – camera focuses on a subject in the central area of the screen. Focus adjusts according to the distance of the subject. Focus • Continuous auto focus – – focuses continually on a subject; useful when shooting slow moving subjects. Focus • Spot focus – – camera focuses on a very precise center area of the screen. Focus • Multi Spot – – Eg. 9-area focus, camera automatically focuses using one or more focus points. ISO • ISO is the number indicating a digital camera sensors sensitivity to light. • The higher the sensitivity, the less light is needed to make an exposure. – Eg. 100, 400, 800 etc ISO • ISO 50 - 80 – – for taking photos in bright light; excellent for close-ups, landscape, and portraits. Produces fine detail and image quality. • ISO 100 – – for extra sensitivity with little, if any, reduced image quality. ISO • ISO 200 – – cloudy and overcast days. Acceptable image quality, with some visible noise. • ISO 400 and above – – suitable for indoor photography whether or not a flash is used. Useful for "stopaction" and sports photographs. Most compact digital cameras produce high to very high image noise. Lenses Lenses • Fixed focal length lens – The camera lens does not change at all. – With a fixed focal lens the only way you can get a close up of a shot is to move closer to your subject. Lenses • Zoom – Optical – An optical zoom is a true zoom. – Its focal length actually extends and retracts. – An image is magnified by the lens itself. Very long zooms are prone to camera shake, particularly in low light. Lenses • Zoom – Digital – A digital zoom is not a true zoom. – It is a simulated zoom that enlarges the central portion of an image. – Resolution is reduced, giving the appearance of zooming in. ?? Questions ?? Slide Show Available For Download www.justnicephotography.com.au/icc.htm FEB07