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i-Link: Name brand used by Sony for FireWire connections. See FireWire.
IEEE 1394: See FireWire.
Image Processor (Digital Camera): The image processor takes the information from the camera’s sensor and converts it to photographic files such as jpgs. The image processor can have a profound impact on image quality. Some manufacturers have branded their image processors, such as DIGIC (Canon) PRIME (Pentax) and TruePic (Olympus).
Image Retention: A more politically correct, nice sounding term for Burn-in. See Burn-in (Televisions).
Image Stabilizer: Image stabilizers are used in cameras, SLR lenses and camcorders to reduce image blur caused by hand movement at low shutter speeds and long focal lengths. Different technologies are employed by different manufacturers. See Image Stabilizer (Digital), Image Stabilizer (Optical), Image Stabilizer (Sensor-based).
Image Stabilizer (Digital): Digital stabilizers use digital processing or raise ISO speeds. Digital stabilization is not true stabilization, is the least effective of stabilization techniques and can degrade image quality.
Image Stabilizer (Optical): Image stabilization using gyroscopically controlled, motor-driven lens elements to compensate for hand movement. It is the most effective method of image stabilization. When used in SLR cameras the optical stabilizer must be built into the lens. Because it is not practical to build an image stabilizer into each and every lens a manufacturer produces, a camera owner may not have an outfit that is 100% stabilized. See Image Stabilizer (Sensor-based.)
Image Stabilizer (Sensor-based): Image stabilization with the sensor mounted on a gyroscopically controlled, motor-driven platform, which moves to compensate for hand movement. Because the stabilizer is built into the camera itself, every lens mounted on the camera will be stabilized. This is a very large advantage to the user, who will enjoy the benefit of stabilization with every lens in every shooting situation. Lenses are also less expensive as they do not have the extra expense of an optical image stablizer. Though sensor-based stabilizers provide excellent performance, optical stabilizers tend to be somewhat more effective in challenging situations, which is a reason some manufacturers still prefer optical to sensor stabilization. See Image Stabilizer (Optical.)
Impedance: Electrical resistance, given in ohms and most commonly seen in speaker specifications such as 4 ohms, 8 ohms, etc. The lower the impedance, the more robust of an amplifier is required to drive them. See Ohms, Current.
Incident Meter Reading: Light meter reading taken by measuring the light falling on the subject. Incident readings are extremely accurate because they are unaffacted by backlighting or other challenging lighting situations, but usually require a hand-held meter. Lens attachments are available to convert a camera meter to an incident meter. See 18% Gray, Light Meter.
Integrated Amplifier: Audio component that combines a preamplifier and an amplifier in a single chassis. It could also be considered a receiver without a tuner. See Amplifier, Preamplifier, Receiver and Tuner.
Interlaced scan: Video signal drawn in two passes, unlike a progressive signal which is drawn in a single pass. Interlaced scan is considered inferior to progressive scanning, though interlaced video is still capable of extremely high quality. NTSC is an interlaced scan format (480i) as is 1080i, the most commonly used HDTV broadcast resolution. See Progressive Scan.
Interconnect: Cable used to connect one component to another. (Don’t spend too much on these, it is a big waste of money!) See Snake Oil.
Invar Shadow Mask: A screen made of Invar, a heat resistant nickel-steel alloy. Invar shadow masks were used in the construction of high-end CRT television picture tubes because they would not warp when driven to high temperatures, allowing the television to have a brighter, sharper picture.
Invert phase: Changing the orientation of an audio waveform by 180 degrees. Some audio components will allow you to invert phase to improve sound quality (specifically subwoofer bass response) in certain situations.
ISO (Entity): International Standards Organization., entity responsible for establishing international standards for industry, government and the private sector.
ISO (Photography): Light sensitivity rating of photographic film or a digital camera’s image sensor. Doubling the ISO number doubles the sensitivity, which is an increase of one f-stop. The ISO rating scale in 1/3 stops is 12, 16, 25, 32, 40, 50, 64, 80, 100, 125, 160, 200, 250, 320, 400, 500, 640, 800, 1000, 1250, 1600, 2000, 2500, 3200, 4000, 5000, and 6400, etc. Camera supporting up to ISO 25,000 have been introduced, but most consumer cameras have a maximum between ISO 800 and ISO 3200. Photographic film has typically had a minimum of ISO 25, with ISO 100, ISO 200, and ISO 400 as the most popular. See f-stop, Exposure.
