Video FAQ

1 Looking for Secondhand Video Equipment?
2 Looking for the Pin Out for a Connector?
3 Looking for a Video Hire Company?
4 Computer Based Visuals anyone?
5 Screen Resolutions
6 Video Standards
7 Where can I get images, photos or pictures?
8 Recommended Reading
9 To be written:

Looking for Secondhand Video Equipment?

You've tried Google and it's friends? No, well stick 'secondhand video equipment' into a search engine and prepare to be amazed at how many results you get. Narrow it down by adding your country, region or nearest large town.
e-bay is full of the stuff.
Failing the above, here is a list of a few regular dealers in professional video equipment, it's by no means complete and biased towards the UK...

Looking for the Pin Out for a Connector?

Looking for a Video Hire Company?

Visit our Friends at Stagelink, who list all sorts of video suppliers.

AV Hire Companies Listed By County - Ukslc.org

Computer Based Visuals anyone?

Again, not complete...

Resolume
ArKaos
Livid Union
Pilgrim
AV Mixer
VJamm
Isadora
Screen Monkey (free)
VVVV (free)
PCStage (using the MediaSync plugin, free but from V4.7.0 certain multimedia functionality will gracefully die about an hour after starting the program unless a small fee is paid)
QLab
Visual Jockey (free)
VJ Central - Does for VJ's what Blue Room does for Production people

Screen Resolutions

The most commonly encountered screen resolutions are below, for a full list, have a look at the Screen Resolutions page.

VGA (Video Graphics Array) = 640 x 480
SVGA (Super Video Graphics Array) = 800 x 600
XGA (eXtended Graphics Array) = 1024 x 768
SXGA (Super eXtended Graphics Array) = 1280 x 1024
UXGA (Ultra eXtended Graphics Array) = 1600 X 1200

A great representation in easy to understand terminology for screen resolution and how they represent the screen ratios (ie 4:3, 16:9, etc) can be found here at the Wikipedia site.

Video Standards

Luminance - the brightness of a video image. Also known as 'Y'.

Chrominance - the colour of a video image. Usually comprising two signals called 'U' and 'V' (or 'I' and 'Q' in the US).

PAL - Phase Alternating Line The composite video standard used in the UK and most of Europe. Almost always used as 625 lines per frame and 25 frames per second.

NTSC - National Television System Committee The composite video standard used in the USA, Canada, Mexico and Japan. Uses 525 lines per frame and 29.97 ("30-drop") frames per second.

SECAM - SEquentiel Couleur Avec Memoire

Composite - Luminance and Chrominance are combined together using PAL, NTSC or SECAM. The process restricts the bandwidth (resolution) of the components. It is easy to add the signals together but difficult to reverse the process. The complete signal is carried on a single wire.

Component - Luminance and Chrominance remain as separate signals. Usually component is taken to mean a YUV signal but RGB is also a component signal. Uses 3 wires.

RGB - a video format where the Red, Green and Blue components of a video image are processed and transmitted separately. Uses 3 wires.

YUV - see Component above.

YC - a video format where the luminance and chrominace signals are handled separately (also known as S-Video). C is made by mixing the two, U and V, components. Uses 2 wires.

S-Video - see YC above.

Line - a video picture is made by scanning a scene in both the horizontal and vertical directions at the same time. One scan from side to side is called a 'line'

Field - a complete scan from top to bottom, made up of odd or even lines, is a 'field'. Line 1, 3, 5 etc are scanned in the first field, followed by 2, 4, 6 etc in the second field.

Frame - in most video systems two fields are interlaced to make a 'frame'.

Sync or Syncronising Signal - to keep the scan process in all the interconnected pieces of equipment in step with each other a special signal is tranmitted along with the picture. This is the Sync signal. It can be sent added to one of the video signals or down a separate wire.