Calibrating Tv screen without blue

patreb wrote on 1/19/2005, 12:59 PM

You know how you can turn on blue only channel on professional monitors and then calibrate accordingly. Someone told me that you can use dense blue gel and look at monitor through that gel to get similar effect. Anyone knows whether it would work with Lee's blue gels if so which ones.

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musman wrote on 1/21/2005, 1:39 PM

Gary, I know you know ton more about pretty much anything related to video than I do, but I confused how there's not a digital to analog conversion here. Vegas to firewire to pd150 is digital. S-video out from pd150 to Panasonic TV set is analog, right?

GaryKleiner wrote on 1/21/2005, 2:18 PM

Musman,

Yes, there is a D/A conversion, but that doesn't involve the CAMERA processing that takes place when you are shooting and converting light into a digital signal. THAT is where the camcorder effects the pedistal, not when it transcodes an incoming DV signal, unless I am mistaken (which is possible, but I don't think so).

Gary

musman wrote on 1/21/2005, 8:33 PM

Now I could be wrong, but I could have sworn I read that the pd150 worked this way:
1- you can apply 7.5 setup (pedistal) in the pd150's settings and that adds pedistal to your production (on the tape). The advice I've heard is never to use this option.
2- Any analog out from the camera gets 3.7 IRE added by the camera. This happens when viewing live footage, viewing a dv tape in the camera, or when if you use the pd150 as a passthrough transcoder (firewire in- s-video or composite out). I believe the reason it does this is you don't have to add 7.5 pedistal if you stay in the digital realm, but if you live in the USA and go from digital to analog then you need to add 7.5 IRE as our TVs are designed for it. Japanese NTSC does not require or expect pedistal, so ideally there the camera should add nothing. But, to split the baby Sony took the middle road and has the camera add 3.7 IRE to all analog outputs from the camera. Therefore monitoring the pd150 from any analog output or using it as a transcoder will always have a slightly improper black level. No one said you had to use the camera as a transcoder, but for live monitoring during production, this sucks for a 'professional' camera. However, I believe only JVC doesn't do this exact same thing or something close to it.
Anyway, basically I was told that in USA NTSC we should add 7.5 IRE for previewing on an external monitor and to any analog tapes we make. This is why the Canopus advc100 is a nice model as you can have it add or not add pedistal as needed. Thus, it can add pedistal to outputs (which we need) but not add it for inputs- and all of this is done as hardware so it's realtime.
I believe dvds work differently. Material bound for a dvd for USA NTSC doesn't have to add pedistal as the players here add it for us. However, Japanese dvd players don't add pedistal as their TVs shouldn't have it. This is why you should never buy a dvd player meant for us in Japan even though it is NTSC.