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| General Terms and Vocabulary in the Camera World |
CMOS: Complementary Metal-Oxide Semiconductor: one of the two main types of image sensors used in digital cameras. Its basic function is the same as that of a CCD. Compression Format: Method used to represent and store images in a smaller more compact form without sacrificing much video quality. The trend is towards more sophisticated formats that are able to compress video smaller and smaller. MPEG-4, the *******current state of the art, ************* absorbs many of the features of MPEG-1 and MPEG-2 and other related standards while adding new features as well. Digital video cable: A cable that can transmit a digitally represented image (in its original digital form) from the camera head to the recording unit . Technically reffered to as a low-voltage differential signal, or LVDS, this type of signaling is used behind the scenes in many high-speed data transfer protocols such as FireWire, Serial ATA, SCSI, and more. Non-digital cables send a converted analog signal which is then reconverted back into digital form by the recording unit for storage. Digital video cables produce better images as information is not lost in a conversion process.*********** DVR: Digital Video Recorder. A small device that can record video and audio, typically onto solid state flash memory such as an SD card. Some DVRs are sold seperate from the camera head and cable, and others are sold as a package where the camera head and cable are included. When comparing the cost of different systems don't forget to take note of whether the advertised price is for the DVR alone, or for a complete helmet camera system. External Microphone: microphone located seperately at the end of a wire pluged into the recording unit. Allows user to located microphone in an ideal place for recording sound that will accompany recorded video images. FPS (frames per second): In this case, the number of images per second captured by the recording unit of the helmet camera system. Anything less than 25 FPS can result in noticeably choppy, discontinuous movement during video playback. Hermetically sealed: A hermetic seal is an airtight seal. The camera lens chambers containing the image sensory is typically sealed in this way to prevent fogging or debris from distorting the image quality. Integrated: Not to be confused with "all in one" camera systems that have a camera and DVR located together in the same unit, integrated camera systems have a microphone and camera head that are seprate from the main recording unit yet draw power from its battery. Integrated units are typically designed with point of view filming in mind and typically mean less wire clutter and better overall usability (see "Usability"). According to HCC guru Chad a fully integrated helmet cam system will meet the following requirements: • Provide an easy and efficient user experience • Will have a recording unit designed around the uses associated with wearable video. Shock, temperature, water, long recording times. • One power source for the whole system, preferrably inside the recording unit to protect it from the elements. This means the camera draws power from the recording unit. • Strong and waterproof connectors designed to be beat up - aka duct tape not required. • A remote control that interacts with the recording unit and camera. Interchangeable lenses: Many manufacturers makes separate lenses that can be installed in the same camera head or they produce multiple camera heads with different types of lenses in each. While it is more expensive to buy different camera heads with different lenses as apposed to swapping out different lenses in the same camera head, it doesn't require the delicate task of changing lenses using tweezers, and it doesn't mean breaking the hermetic seal (see "hermetic seal" above) which can create problems with image quality. Inline Microphone: microphone incorporated into the cable that connects the camera head to the recording unit. Eliminates the need for a seperate microphone wire and thereby reduces users "clutter factor" LANC: *********** LCD: Liquid Crystal Display. A low-power monitor often used on digital imaging devices. Lense View: In this case, expressed in degrees, action and point of view video often requires a larger field of view for better overall viewer enjoyment. This often means a 70 degree lense view or larger. Offering a larger, sweeping perspective, and better depth of field and reproduction than a standard camera lens, wide angle lenses put the subjects action into context, adding landscape or the action of others nearby into the "storyline" of the video. "Fish eye" lenses are extremely wide angle lenses (100 degress or more) that add so much horizontal "context" that the image is distorted or convex in appearance. (lense view can also be indicated with a millimeter measurment. For example, 2.6mm lense = 120 degree lense view, 3.6mm = 92 degree, 4.6mm = 78 degree, 6.0mm lens = 54 degree, 8.00mm=39 degree, 16.0mm=19 degree.) Lipstick camera: (also know as a helmet or bullet camera) an extremely small camera which is approximately the size of a typical tube of lipstick. They are especially useful for capturing images with helmet camera systems where a conventional camera would not work due to size or weight constraints. LUX Rating - Lux is the measurement of light intensity, The lower the LUX rating of a helmet camera the better it will be able to record images in dark, or low light, situations. For filming at dusk or dawn, or poorly lit indoor rooms, or stormy conditions, a helmet camera with a low LUX rating is very important. Loop Mode/Function: Allows user to discard unwanted video footage from short-term memory so that it does not take up the storage capacity of the main flash memory (usually and SD card) For details on how the POV.1 loop mode works go to the Owner's manual p. 27 ***********link to owners manual Mounts: Facilitate the attachment of the camera to various surfaces and locations depending on the point of view desired. Basic mount types include head or helmet style mounts, camera to frame (bike, car, moto, glider, etc.), camera to smooth surface via suction cup (windshield, car hood, helmet, etc.), and adjustable/flexible mounts many inches or feet long that bring the camera away from the mounted to surface giving a unique vantage point. Many mounts types are available from camera manufacturers, and even more can be invented or fabricated by the creative videographer. MPEG4: Moving Picture Experts Group 4. MPEG4 is the most recent version of a standard for the digital representation of video, audio and certain types of 3D information. mAh: Milli-amp Hour: A rating used in the consumption of power of an electronic device. It is also used in reference to the storage capability of a device like an Li-On, NiMH, or NiCad rechargeable battery. NTSC and PAL: NTSC is the format used on televisions in North, Central, and many South American countries. Pal is the format used in most European, Asian, African countries as well as Australia. Don't know what format your country uses?, go to this link to find out: http://en.wikipedia.org/wiki/Image:NTSC-PAL-SECAM.png **********hot link this Proprietary Battery: Battery is unique to a particular helmet camera and can only be purchased from its manufacturer. This will usually result in a more expensive replacement cost. Resolution: The number of horizontal and vertical lines , or pixels, that can be counted from one side of an image to the other. Particular attention should be payed to the number of horizontal lines. If the number of vertical lines of resolution is greater than 480, the image quality does not improve, whereas improving the number of horizontal lines is virtually limitless. Currently helmet camera systems that don't produce horizontal lines in the 600 range are considered sub-standard. The resolution capabilites of the DVR is as (or more) crucial than that of the camera in that a high resolution camera cannot record its crisp image if the DVR unit that it sends its images to is incapable of recording at the same or higher resolution than its camera. SD Card: (Secure Digital Card) A small flash memory card that is used in many of todays portable electronics. Currently comes in regular (SD), mini, and micro sizes. ************* Useability: Our way of scoring a product in terms of overall ease of use. For example, how easy it is to mount the camera using the manufacturer's mounts, or how easy is it to navigate through menu settings, or how easy is it to start and stop recording "in the field"? "Useability" will not neccisarily reflect the units price, or its resolution, or other technical specifications, but is instead focused on the camera's design as it relates to user interface. Is changing the batteries and SD card quick and easy? Can you tell when the remote has signaled the DVR to begin recording? For more on how we arrived at the useability rating for a specific camera, see the individual camera reviews at the HCC blog. Tag Function: A feature that allows a user to mark a point of interest while recording by simply pressing a "tag" button (usually via remote control). The resulting bookmark or "tag" allows one to quickly reference these points of interest during editing or reviewing of the video footage. White balance: White balance (WB) is the process of removing unrealistic color casts, so that objects which appear white in person are rendered white in your video or photo. Since white light is the sum of all other colors, the camera will then display all colors correctly. While "automatic white balance" can have two different interpretations, on consumer-level cameras, it means completely automatic.
Last update: 06:47 PM Tuesday, March 4, 2008 |
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