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Macro
Lens
A
lens that provides continuous focusing from infinity to extreme
close-ups, often to a reproduction ratio of 1:2 (half life-size) or
1:1 (life-size).
Macro
Zoom Lens
A
macro lens is designed to capture a tiny subject as a bigger image,
while suppressing the aberrations that tend to be more noticeable in
closer focusing distances. A macro magnification is expressed
in 1: x, which is a ratio of the actual size of a subject [1] to the
size of the subject image reproduced on the film plane [1/ x].
Therefore, the larger the x value becomes, the smaller the
reproduced image on the film plane. For example, an image of a
coin reproduced on film as the same size as the actual coin is 1:1
macro, while the same image reproduced at 1/2 of the original size is
1:2 macro. The macro ratio is also referred to as magnification
ratio, and the maximum ratio of a lens' reproduction capability is
designated as "maximum magnification ratio".
Macro zoom is a specific type of shooting that magnifies the size of
a subject. Therefore, the same effect can be achieved by using
a zoom lens or a telephoto lens to place some distance from the
subject as long as the lens offers a sufficient magnification ratio.
Manual
Iris
Diaphragm controlled
directly by a calibrated ring on the lens barrel.
MATV
It
is the abbreviation for Master Antenna Television.
Media
Access Control address, MAC address
A
MAC address is a unique identifier associated with a piece of
networking equipment, or more specifically, its interface with the
network. For example, the network card in a computer has its own MAC
address.
Megabyte
(MB)
1,048,576
bytes, though often interpreted as 1 million bytes.
Mega
Pixel
Some
digital cameras are described as 1.3/2.1/6.0 Mega Pixel cameras.
1 Mega is 1 million. If the camera produces pictures that are
1280 x 960 pixels, it is 1,228,800 pixels or 1.2288 Mega Pixels.
But the manufacturers round up and call it a 1.3 MegaPixel Camera.
But all cameras were not created equal! Just because a camera
says it is a 2.1 Mega Pixel Camera does not mean it has the same
quality as another camera reported to be a 2.1 Mega Pixel Camera!
There are 2 things to Consider: 1. How many pixels do the camera
produces 2. How many pixels is the CCD (sensor) inside the camera.
CCD sensor is the little sensor that records the picture when you
"snap" the shutter. This
sensor has X number of pixels. Some cheaper cameras use a cheaper CCD
sensor that has a smaller number of pixels then the camera produces.
These cameras then "Resize" the picture, to produce a
larger number of pixels. Just so they can claim their camera is a 1.3
MegaPixel Camera. But the CCD sensor is probably much less. For
camera purchaser, make sure you check the technical specifications of
the camera's CCD Array Size before purchasing.
Memory
Generally,
the fast semiconductor storage (RAM) directly connected to the
processor that depends on electrical power for activation. Memory is
often differentiated from computer storage (for example, hard disks,
floppy disks, and CD-ROM disks) that does not depend on electricity
and is therefore a more permanent means for holding data.
Micro
lens
A
lens for close-up photography; designed to focus continuously from
infinity down to a reproduction ratio of 1: 2, or with a matched
extension ring or tele-converter down to 1: 1; available in normal or
telephoto focal lengths to provide a variety of free working
distances.
Micron
It
means millionth of a meter. ( μ
is a common abbreviation).
Modem
It
was MOdulator-DEModulator until the late 1990s. Modem refers to
a device that allows a computer or terminal to transmit data over a
standard dial-up telephone line. Since the advent of cable and DSL
connections, the term also refers to high-speed broadband modems.
The transmitting modem
translates digital computer data into analog signals that can be
carried over a phone line. The receiving modem translates the analog
signals back to digital form.
Motion
JPEG, MJPEG
Is
an informal name for multimedia formats where each video
frame
or interlaced
field of a digital
video
sequence is separately compressed
as a JPEG
image.
It is often used in mobile appliances such as digital
cameras.
Motor
Drive
A
mechanism for advancing the film to the next frame and recocking the
shutter, activated by an electric motor usually powered by batteries.
Moving
Picture Experts Group, MPEG
MPEG
has standardized the following compression formats and ancillary
standards:
MPEG-1:
Initial video
and audio
compression
standard. Later used as the standard for Video
CD,
and includes the popular Layer 3 (MP3)
audio compression format.
MPEG-2:
Transport, video and audio standards for broadcast-quality
television. Used for over-the-air digital
television
ATSC,
DVB
and ISDB,
digital satellite TV services like Dish
Network,
digital cable
television
signals, SVCD,
and with slight modifications, as the .VOB
(Video Object) files that carry the images on DVDs.
MPEG-3:
Originally designed for HDTV,
but abandoned when it was realized that MPEG-2 (with extensions) was
sufficient for HDTV. (not to be confused with MP3,
which is MPEG-1 Audio Layer 3.)
MPEG-4
MPEG-4
is a collection of methods defining compression of audio and visual
(AV) digital data. It was introduced in late 1998 and
designated a standard
for a group of audio and video coding formats and related technology
agreed upon by the ISO/IEC
Moving Picture Experts Group (MPEG) under the formal standard ISO/IEC
14496. Uses of MPEG-4 include compression of AV data for web
(streaming media) and CD
distribution,
voice (telephone,
videophone) and broadcast television
applications. MPEG-4 absorbs many of the features of MPEG-1
and MPEG-2
and other related standards, adding new features such as (extended)
VRML
support for 3D rendering, object-oriented
composite files (including audio, video and VRML objects), support
for externally-specified Digital
Rights Management
and various types of interactivity. AAC (Advanced Audio Codec) was
standardized as an adjunct to MPEG-2 (as Part 7) before MPEG-4 was
issued.
Most
of the features included in MPEG-4 are left to individual
manufacturers to decide whether to implement them. This means that
there are probably no complete implementations of the entire MPEG-4
set of standards. To deal with this, the standard includes the
concept of "profiles" and "levels", allowing a
specific set of capabilities to be defined in a manner appropriate
for a subset of applications.
Initially,
MPEG-4 was aimed primarily at low bit-rate
video
communications;
however, its scope was later expanded to be much more of a multimedia
coding standard. MPEG-4 is efficient across a variety of bit-rates
ranging from a few kilobits per second to tens of megabits per
second. MPEG-4 provides the following functionalities:
Improved
coding efficiency
Ability
to encode mixed media data (video, audio, speech)
Error
resilience to enable robust transmission
Ability
to interact with the audio-visual scene generated at the receiver
MPEG-4.ASP
To
address various applications ranging from low-quality, low-resolution
surveillance cameras to high definition TV broadcasting and DVDs,
many video standards group features into profiles and levels. MPEG-4
Part 2 has approximately 21 profiles, including profiles called
Simple, Advanced Simple, Main, Core, Advanced Coding Efficiency,
Advanced Real Time Simple, etc. The most commonly deployed profiles
are Advanced Simple and Simple, which is a subset of Advanced Simple.
Most
of the video compression schemes standardize the bit stream (and thus
the decoder) leaving the encoder design to the individual
implementations. Therefore, implementations for a particular profile
(such as DivX
or Nero
Digital
which are implementations of Advanced Simple Profile and Xvid
that implements both profiles) are all technically identical on the
decoder side. A point of comparison would be that an MP3 file
can be played in any MP3 player, whether it was created through
iTunes, Windows Media Player, LAME
or the common Fraunhofer encoder.
Simple
Profile is mostly aimed for use in situations where low bit rate and
low resolution are mandated by other conditions of the applications,
like network bandwidth, device size etc. Examples are cell phones,
some low end video conferencing systems, surveillance systems etc.
Advanced Simple Profile (ASP)’s notable technical features
relative to the Simple Profile, which is roughly similar to H.263,
include:
Multiplex
It
is a technique for putting two or more signals into a single channel.
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