Digital Cameras Introduction.pdf

UNDERSTANDING RESOLUTION & 1 Digital Cameras Understanding Resolution Resolution is determined by how many pixels (picture elements) or dpi (dots per inch) are available. The image you see is simply a grid of small squares or circles filled in with color. The more squares or cir...

UNDERSTANDING RESOLUTION & 1 Digital Cameras Understanding Resolution Resolution is determined by how many pixels (picture elements) or dpi (dots per inch) are available. The image you see is simply a grid of small squares or circles filled in with color. The more squares or circles—the sharper the image. Measuring Resolution Resolution is measured by the number of horizontal pixels times the number of vertical pixels – Example: 3072 x 2304 Megapixels The quality of a picture is primarily measured by its resolution—how many pixels it has; the current measurement is in megapixels A megapixel is a grid containing one million pixels (one million squares of color)—technically, that is an image with a resolution of 1024x1024 pixels Three Resolutions to Consider Image – Measured in pixels – Can be changed on the camera – High res = clear pix = large file size Monitor – Measured in horizontal vs. vertical pixels. Ex. 1920 x 1200 Printer – Measured in dpi (dots per inch) – Quality of print will depend on image AND printer resolution 5 Digital Cameras There are two primary categories of digital cameras – Point and shoot – Digital Single Lens Reflex (SLR) 6 Point and Shoot Cameras Most digital cameras designed for the consumer (vs. professional) are point and shoot cameras They fall into three categories: subcompact, compact and super zoom The camera lenses are built-in (not removable) Basic features typically include auto focus, auto exposure and built-in flash Not appropriate for action photography because of lag time 7 SLR Cameras (Single Lens Reflex) ⚫ With an SLR camera, you see exactly what the lens sees ⚫ You can change the lens on a digital SLR ◦ You choose the lens based on the type of photography; 8 example: product photography vs. portrait photography vs. sporting events vs. landscape photography, etc. ⚫ SLRs produce higher-quality photos than point and shoot cameras ⚫ An SLR has a near-zero lag time, and is ideal for action photography Other points to consider When purchasing a camera, you should also research the following specifications: – Storage Capacity – Transferring Images – Power Source – LCD vs. Optical Viewfinder – Zoom – Image Stabilization – The Exposure Triangle (Aperture, ISO, Shutter Speed) 9 Storage Devices Memory Card Flash Memory The number of pictures you can take before sending them to your computer is determined by two things: The resolution of the image The type of storage 10 Transferring Images Card reader USB cable Bluetooth 11 Power Source Regular Batteries Rechargeable batteries – Alkaline – Nickel-metal hydride (NiMH) – Lithium-ion (Li-Ion) AC Adapter 12 LCDs vs ViewFinder LCD—Pro’s Viewfinder—Pro’s – Shows you the exact image – Uses less battery that will be recorded – Easier to see images in bright – Easy to view … delete light images, etc. Viewfinder—Con’s – Displays menu – Shows close approximation of LCD—Con’s the final image—not the real – Drains battery—uses ½ life of thing battery – Difficult for some people to – Difficult to see in bright light see 13 Zoom Optical zoom actually enlarges the image – Measured in X Example: 8X—increases an image 8 times Digital zoom takes a portion of an image an enlarges it electronically; – The image loses resolution when the camera enlarges it; also measured in X Macro zoom allows you to take close-up pictures of objects that are small and enlarge them so they appear larger. 14 Image Stabilization A feature in digital cameras that reduces the vibrations that can occur when taking a picture. – Vibrations commonly occur when shooting at slow shutter speeds, with longer lenses or with digital zoom. – Also called anti-shake 15 The Exposure Triangle Exposure is the total amount of light you let into your camera. – Too much light results in an over-exposed image where there are areas of bright white or ”blow-outs”. These areas contain no detail or color. – Too little light and an under-exposed image leaves parts of your image too dark to make out details. The three components to exposure are ISO, shutter speed and aperture Camerasim.com 16 The Exposure Triangle ISO—the measurement of how sensitive the image sensor in the camera is to light. – Measured in numbers 100, 200, 400, 800, etc. – Use a lower number when smooth crisp images are need and you have plenty of light. – Higher numbers are used when light is limited, you do not want to use a flash, or the subject is moving; may result in grainy images 17 The Exposure Triangle Shutter Speed—the amount of time the shutter is open—which determines how much light is captured in the recording process – Measured in seconds: super fast 1/2000 second to 30 seconds – The slower the speed, the longer light can enter the camera. Appropriate for shooting pictures in darker situations; also great for freezing action and movement 18 The Exposure Triangle Aperture—the camera feature that regulates the amount of light that passes through the lens by controlling the size of the opening in the lens – Described as the f/stop (a stop is a change in setting) – The smaller the number the wider the lens will open 19 20 21