The single-lens reflex (SLR) camera uses an semi-automatic moving mirror system which permits the photographer to sometimes see exactly what will be captured by the film or digital imaging system, as opposed to pre-SLR cameras where the view through the viewfinder could be significantly different from what was captured on film.
Most SLR cameras permit upright and laterally correct viewing through use of a pentaprism situated in the optical path between the reflex mirror and viewfinder. Light is reflected by a movable mirror upwards into the pentaprism where it is reflected several times until it aligns with the viewfinder. When the shutter is released, the mirror moves out of the light path and the light shines directly onto the film, or in the case of a DSLR, the CCD or CMOS imaging sensor.
Focus can be adjusted manually by the photographer or automatically by an autofocus system. The viewfinder can include a matte focusing screen located just above the mirror system to diffuse the light. This system permits accurate viewing, composing and focusing, especially useful with interchangeable lenses.
The single-lens reflex (SLR) camera uses an semi-automatic moving mirror system which permits the photographer to sometimes see exactly what will be captured by the film or digital imaging system, as opposed to pre-SLR cameras where the view through the viewfinder could be significantly different from what was captured on film.
Prior to the development of SLR, all cameras with viewfinders had two optical light paths: one path through the lens to the film, and another path positioned above (TLR or twin-lens reflex) or to the side (rangefinder). Because the viewfinder and the film lens cannot share the same optical path, the viewing lens is aimed to intersect with the film lens at a fixed point somewhere in front of the camera. This is not problematic for pictures taken at a middle or longer distance but parallax causes framing errors in close-up shots. Moreover, focusing the lens of a non-reflex camera when it is opened to wider apertures (such as in low light or while using low-speed film) is not easy.
Most SLR cameras permit upright and laterally correct viewing through use of a pentaprism situated in the optical path between the reflex mirror and viewfinder. Light is reflected by a movable mirror upwards into the pentaprism where it is reflected several times until it aligns with the viewfinder. When the shutter is released, the mirror moves out of the light path and the light shines directly onto the film, or in the case of a DSLR, the CCD or CMOS imaging sensor.
Focus can be adjusted manually by the photographer or automatically by an autofocus system. The viewfinder can include a matte focusing screen located just above the mirror system to diffuse the light. This system permits accurate viewing, composing and focusing, especially useful with interchangeable lenses.
Up until the 1990s, SLR was the most advanced photographic preview system available. But the recent development and refinement of digital imaging technology with an on-camera live LCD preview screen has overshadowed SLR’s popularity. Nearly all inexpensive compact digital cameras now include an LCD preview screen allowing the photographer to see exactly what the CCD is capturing. However, SLR is still popular in high-end and professional cameras, because the pixel resolution, contrast ratio, refresh rate, and color gamut of an LCD preview screen cannot compete with the clarity and shadow detail of a direct-viewed optical SLR viewfinder.
IP cameras are Closed-circuit television (CCTV) cameras that use Internet Protocol to transmit image data and control signals over a Fast Ethernet link. As such, IP cameras are also commonly referred to as network cameras. IP cameras are primarily used for surveillance in the same manner as analog closed-circuit television. A number of IP cameras are normally deployed together with a digital video recorder (DVR) or a network video recorder (NVR) to form a video surveillance system.
The terms IP camera and network camera are most commonly used to refer to surveillance cameras with a Fast Ethernet interface. In this context, the term IP camera does not include GigE vision camera, which is a machine vision camera with a Gigabit Ethernet interface.
IP Camera Features
2 way audio allow users to communicate what they are seeing (e.g. Gas station clerk assisting a customer on how to use the prepay pumps).
LED lighting which is used for night vision. This feature gives users the ability to view low light areas, known as Night Vision.
Ability to view at a streaming rate, some IP cameras have a resolution of 640×480 and are able to record at 30 frames per second.
IP cameras are also able to function on a wireless network. Initial configuration has to be done through a router, however after the IP camera is installed it can then be used on the wireless network.
Camera
A camera is a device that records images, either as a still photograph or as moving images known as videos or movies. The term comes from the camera obscura (Latin for “dark chamber”), an early mechanism of projecting images where an entire room functioned as a real-time imaging system; the modern camera evolved from the camera obscura.
Cameras may work with the light of the visible spectrum or with other portions of the electromagnetic spectrum. A camera generally consists of an enclosed hollow with an opening (aperture) at one end for light to enter, and a recording or viewing surface for capturing the light at the other end. A majority of cameras have a lens positioned in front of the camera’s opening to gather the incoming light and focus all or part of the image on the recording surface. The diameter of the aperture is often controlled by a diaphragm mechanism, but some cameras have a fixed-size aperture.
A typical still camera takes one photo each time the user presses the shutter button. A typical movie camera continuously takes 24 film frames per second as long as the user holds down the shutter button.
Digital camera
A digital camera (or digicam for short) is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor.
Front and back of a Canon PowerShot A95.
Many compact digital still cameras can record sound and moving video as well as still photographs. In the Western market, digital cameras outsell their 35 mm film counterparts.[1]
Digital cameras can do things film cameras cannot: displaying images on a screen immediately after they are recorded, storing thousands of images on a single small memory device, recording video with sound, and deleting images to free storage space. Some can crop pictures and perform other elementary image editing. Fundamentally they operate in the same manner as film cameras, typically using a lens with a variable diaphragm to focus light onto an image pickup device. The combination of the diaphragm and a shutter mechanism is used to admit the correct amount of light to the imager, just as with film; the only difference is that the image pickup device is electronic rather than chemical.
Digital cameras are incorporated into many devices ranging from PDAs and mobile phones (called camera phones) to vehicles. The Hubble Space Telescope and other astronomical devices are essentially specialised digital cameras.
iPod users commonly store their entire music and picture collections on iPod digital audio-video player. Sometime due to accidental deletion or improper knowledge about the iPod functioning the files are deleted or lost from the music device.
iPod music recovery software recovers data from all major Apple iPod models including iPod Shuffle, iPod Nano, iPod Mini, iPod first generation to latest generation series (iPod with video) in major storage capacity that includes 512MB, 1GB, 2GB, 4GB, 20GB, 40GB, 60GB, and 80GB audio video models etc. iPod restore software is used to retrieve music, images, pictures; audio, video, digital images lost due to accidental formatting, deletion. Data Doctor iPod data recovery software is very easy to use and rescue lost files and folders easily.
Features of iPod Data Recovery Software
- Restore lost music, photos, and deleted songs from formatted or logically damaged iPod memory.
- iPod data retrieval software support all file formats including audio files (aiff, wav, mp3, m4a, Apple lossless etc), video files (mpeg4, Quick Time etc) and picture files (jpeg, jpg, bmp, gif, png etc.
- Ensures from accidentally formatted iPod memory or when data reset operation is being performed on iPod device.
- Recover data even if iPod partition volume is not recognized by the system.
- Retrieve corrupted, damaged files and folders from the iPod storage disk.
- Ensure music recovery when updated or restored using iTunes software.
- Easy to operate for the non-technical background person!
Operating system supported
- Windows 98, NT, ME, 2000, 2003 server
- Windows Vista, XP (Home, Professional, Media center edition)
System Requirements
- Pentium AMD Intel or equivalent processor
- 128 MB RAM
- 10 MB of free hard disk space for installation
Software Interface Languages
