"What is a Shaped Key?" -

Most key sources produce a fill signal that is larger than the key signal...this allows a key signal to have soft edges and gradiated mattes that when filled with video cause the resultant key to have transparancies - this is called Unshaped video.  When a switcher processes a keyed source, the switcher multiplies the fill signal times the key signal.  The excess video signal is then equal to the size of the key signal - this is called Shaped video.  Usually, once a source goes through a keyer, the excess video is lost and the video will always be Shaped.  If your fill signal graphics off your server look bright & undefined, they are probably Unshaped.

Many devices such as CG's now have the ability to take in video & do their own processing.  The result is an already-shaped key where the fill & key signal are equal in size.  If the switcher tries its multiplication trick on already-shaped video, the result is a key that has black edges around the outside.  So switchers have settings that let you do additive keying to get around this.  On the GV switchers it is called FORCED SHAPING, while on the SONY's it is called CLEAN KEY.  This multiplicative / additive mode selection is also available on Chroma Keys - additive mode works well with things like smoke, fog, and water where you want a lot of soft transparencies...multiplicative mode works best when you have talent where you want a defined outline of the person.

The default mode for most switchers is to always try and shape the key, so the switcher is normally expecting an unshaped source.

The easiest way to tell if your incoming signal is Shaped or Unshaped is to key it over a bright gray with no edging (have your CG Op type a white font with no drop shadows or borders).  If it's unshaped video & your switcher is set to do a multiplicative key, the edges will look clean - if you see black edges around your key, then you have the wrong keying mode selected (although you might like the look and want to stay with it).  On the GV switchers you can fix this either in the ENG / Sources menu or in the keyer menu...on the SONY it's done by turning on (or off) the CLEAN KEY button in the keyer menu.

"What is a Shaped Key?" -

Most key sources produce a fill signal that is larger than the key signal...this allows a key signal to have soft edges and gradiated mattes that when filled with video cause the resultant key to have transparancies - this is called Unshaped video.  When a switcher processes a keyed source, the switcher multiplies the fill signal times the key signal.  The excess video signal is then equal to the size of the key signal - this is called Shaped video.  Usually, once a source goes through a keyer, the excess video is lost and the video will always be Shaped.  If your fill signal graphics off your server look bright & undefined, they are probably Unshaped.

Many devices such as CG's now have the ability to take in video & do their own processing.  The result is an already-shaped key where the fill & key signal are equal in size.  If the switcher tries its multiplication trick on already-shaped video, the result is a key that has black edges around the outside.  So switchers have settings that let you do additive keying to get around this.  On the GV switchers it is called FORCED SHAPING, while on the SONY's it is called CLEAN KEY.  This multiplicative / additive mode selection is also available on Chroma Keys - additive mode works well with things like smoke, fog, and water where you want a lot of soft transparencies...multiplicative mode works best when you have talent where you want a defined outline of the person.

The default mode for most switchers is to always try and shape the key, so the switcher is normally expecting an unshaped source.

The easiest way to tell if your incoming signal is Shaped or Unshaped is to key it over a bright gray with no edging (have your CG Op type a white font with no drop shadows or borders).  If it's unshaped video & your switcher is set to do a multiplicative key, the edges will look clean - if you see black edges around your key, then you have the wrong keying mode selected (although you might like the look and want to stay with it).  On the GV switchers you can fix this either in the ENG / Sources menu or in the keyer menu...on the SONY it's done by turning on (or off) the CLEAN KEY button in the keyer menu.