[filmscanners] Re: CRTs vs LCDs

["Colin Maddock" <cmaddock@clear.net.nz>]

Dave asked:
>Well, I was satisfied by Julian's answer, it was easy and practical.  But
>your answer has me wondering again about what is actually happening at the
>circuit level.  I guess they are voltage amplifiers operating at different
>frequencies?  Presumably the gain control isn't particularly critical in
>real world terms for color correcting work (all I really care about), but I
>wonder why.

The bias controls (three, one for each colour) in effect adjust a voltage on 
one of the CRT electrodes to give individual brightness adjustment of each 
colour. They are set to give neutral blacks.

The gain controls (again, one for each colour) set the gain of the video amps 
in the monitor and are adjusted to give neutral whites. With luck, or a good 
quality monitor, all the grey levels are also neutral, but if not, that is 
where a utility such as Adobe Gamma comes in.

Both white and black settings are important for colour correcting work Dave, 
perhaps the black setting being the more ctitical one.

Colin Maddock
  


----------------------------------------------------------------------------------------
Unsubscribe by mail to listserver@halftone.co.uk, with 'unsubscribe 
filmscanners'
or 'unsubscribe filmscanners_digest' (as appropriate) in the message title or 
body