Re: Profiling a Dell UltraSharp 2405FPW LCD part 1
Re: Profiling a Dell UltraSharp 2405FPW LCD part 1
- Subject: Re: Profiling a Dell UltraSharp 2405FPW LCD part 1
- From: email@hidden
- Date: Fri, 29 Jul 2005 09:50:10 EDT
Split in half for the size filter...
email@hidden writes:
I need to profile a new 24" Dell UltraSharp flat panel display using
a Spyder colorimeter and preCal/Optical the Dell has OSD controls for:
- brightness (which fails to make much of a dent in the brightness)
May be brightness, at video card level, or may be backlight, either way you say it won't go far...
- contrast (inactive, I assume due to the PB card limitations)
Or because you are using a digital instead of analog connection, or some other technical reason...
And it has individual RGB level controls that are labeled:
- (sRGB)
- (warmer image)
- (cooler image)
- User Preset, which allows me to set the RGB levels individually
Then your choices are to set to sRGB (which simply means Gamma 2.2, Whitepoint 6500k, or thereabouts) and ignore PreCAL, or User Preset, choosing 6500 in PreCAL, and balancing the guns. Whichever seems to work best. But don't try to crank the guns (since they aren't really guns) down in PreCAL, simply balance them up at the brightness they start at.
I cranked down the brightness control to zero, and adjusted
the RGB levels downward using PreCal until the white luminance value
was about 95. Since PreCal requires a color temperature to be
selected, and doesn't have a native white point setting, I chose 6500
in PreCal. There no kelvin-based temperature settings on the Dell.
Yes there is: sRGB is 6500k, as well as gamma 2.2. Thats all they mean by it; these same gamma and white point settings also occur in AdobeRGB, they aren't defining the monitor gamut on the fly to sRGB when you choose this, they simply have a fixed gamut in the range of sRGB, and set the gamma and whitepoint to sRGB standards, approximately, when you choose this setting.
Once I finished with PreCal, I fired up Optical, selected 6500 and a
gamma of 1.8 and let 'er rip.
Wrong twice, use Native Whitepoint, as you've already defined a whitepoint elsewhere, and choose 2.2; you don't want to twist this device around by a .4 gamma shift at the video card, that would lose you lots of levels. Photoshop will sort out the gamma if you calibrate to 2.2, and the profile says 2.2. No need to use 1.8 with an LCD.
The resulting profile is obviously wrong. It makes photos too dark
and contrasty. So how should I go about it? Specifically...
I suspect the suggestions above will get you in the necessary range to build a good profile.
- There is such a vast difference between the Dell and the PB display
in terms of brightness, I figure I should forget about trying to get
the two to match. Would you agree?
Yes, dumbing the Dell down to PowerBook luminance, since it does not have a backlight control that goes that far, is a bad idea.
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