I believe that IDC's have a UV AND IR filter as CCD's are sensitive to both. Putting additional filters in front is unlikely to have any effect except to protect the lens. I think a polarising filter would be effective as ccd's do not pickup on polarisation at present. Chris, :> -----Original Message----- :> From: owner-photoforum@xxxxxxxxxxxxxxxxxxxxxx [mailto:owner- :> photoforum@xxxxxxxxxxxxxxxxxxxxxx] On Behalf Of Qkano :> Sent: 08 March 2005 16:53 :> To: List for Photo/Imaging Educators - Professionals - Students :> Subject: Re: Just curious -- monitor resolution :> :> :> :> <<<One is an UV filter to protect the lens in :> really adverse conditions (leaving it on the lens all the time is bad :> practise, like playing a violin without removing it from its case), the :> other would be a polarizer, whose effects would be difficult to :> simulate in PS afterwards.>>> :> :> :> Per :> :> 1) The polarizer is impossible to simulate in PS. :> :> 2) The UV filter has me guessing. :> Are CCD, or for that matter CMOS, sensors particularly sensitive to UV in :> the same way colour film was? Obviously any overall haze caused by UV :> cannot be undone later. It's not a simple matter of colour balance :> :> 3) For mild colour balance effects the only real reason for using a :> filter is I guess to reduce the amount of work post capture (remembering :> to turn auto-colour balance off). For an *extreme* colour cast you are :> trying to correct there is a lot of sense in correcting it first - :> presenting the sensor with a balanced mixture of wavelengths. But this :> extreme is probably beyond anything we meet in outdoor photography. :> :> B :> :> :> :> :> :> -- :> :> Whatever you Wanadoo: :> http://www.wanadoo.co.uk/time/ :> :> This email has been checked for most known viruses - find out more at: :> http://www.wanadoo.co.uk/help/id/7098.htm :>
