From Practice exams Flashcards
What’s the aspect ratio of HDTV?
1.78:1
What’s the resolution of SXGA?
1280 x 1024
What two resolutions count as HDTV?
1920 x 1080(p or i), 1280 x 720p
Is HDTV transmitted analog or digitally?
Analog. Uses compression.
What is SXGA?
Super Extended Graphics Array. Standard monitor resolution, next step above XGA. 1280 x 1024 (1.25:1)
What’s the most common resolution of 17” and 19” LCD monitors?
SXGA. 1280 x 1024
Brightness control adjusts what level?
Black level.
What is Chroma?
The perceived strength of a surface color - it’s difference from grey.
Vectorscopes show…
chroma saturation (color intensity).
What is V-Sync?
For computer monitors. Makes the computer wait until the monitor has finished drawing an image before moving on to the next.
Frames per second can’t be larger than what to avoid sync issues?
Frames per second can’t be larger than your monitor refresh rate (usually between 60 and 90).
What is composite video?
Analog video transmission. Over ONE channel. No audio. Video is SD Usually on RCA jacks. Can be BNC or coax
What are the different ways sync can be sent in component video?
Separate (Red, Green, Blue, Horz Sync, Vert Sync). Composite Sync (Red, Green, Blue, Sync).
Sync-on-Green (Red, Green + Sync, Blue)
Sync-on-luminance (for YPbPr it would be on Y) (home theatre mostly)
What is chrominance?
A combination of hue and saturation.
What is S-video?
Analog video transmission
Standard Def
2 channels: Y (luma (which is luminance and synce)) and C (Chroma)
Doesn’t carry audio
Differences between Composite, S-Video, Component?
Composite: 1 channel (Fine. Low pass filter on luminance)
S-Video: 2 channels (Better)
Component: 3-5 channels (Best)
What connector is used for S-Video
4-pin. 2 signal pins and 2 grounds.
What are examples of composite video?
NTSC (Americas), PAL (Europe), SECAM (Africa, Russia)
What is component video?
Analog video transmission
Doesn’t carry audio
What is YP(B)P(R)?
A way of doing component video. Y=luma & sync, P(B) = difference between Blue and Luma, P(R) = Difference between red and luma.
What is gain in video?
On a CCD camera it’s how many electrons get converted into digital. Maximises dynamic range from each sensor.
What is a watt?
Measure of power - rate that energy is consumed or produces. 1 watt = 1 joule / second
What is an amp?
A unit for electric current. The amount of electrons passing point in a given time. 1 amp = a coulomb / second
What is a volt?
A unit for elctromotive force. The inclination of a system to allow electric current to flow.
What’s standard home voltage in the US?
120V
What’s standard home voltage in Europe/Asia?
230V
As you double distance how does it effect sound and brightness?
Sound will be 6dB less
Brightness will be 75% less
Sound levels should be how much above ambient room noise in a sound system?
25 dB
What’s an advantage of a horn loudspeaker over cone?
More efficient: 10 times (10 dB) more sound than a cone speaker.
What’s a disadvantage for a horn loudspeaker?
Frequency response is uneven. Bad bass response.
What’s the difference between RS-232 and RS-422 serial connections?
- RS-232 only allows for one transmitter and one receiver on each line. Full duplex. Ships standard on most Windows desktops.
- RS422 Faster (up to 10 Mbits/s. One transmitter can connect to a bus of up to 10 receivers. Can transmit further. Standard on Apple computers.
What’s the minimum number of wires needed to connect bidirectional RS-232?
3