Luminous Landscape Forum

Raw & Post Processing, Printing => Colour Management => Topic started by: Tom H. on January 13, 2009, 11:09:07 pm

Title: Colour Space and Calibrating older IBM P260 monitor
Post by: Tom H. on January 13, 2009, 11:09:07 pm
Hi I've read much on the topic but want to make sure I have it straight.

I'm shooting in Adobe RGB colour space.
Using Photoshop in RGB and softproofing with the appropriate paper profile for my Epson 2200
Then using that profile in Photoshop to print, with no ICC profile in my printer software

My monitor's colour menu has an sRGB setting, an "Easy" setting and an "Expert" setting
The easy just lets you set the colour space (I chose 6500), the expert lets you set individual RGB guns (bias and gain) as well as colour space, and sRGB has no options at all.

The black level and gama with Monaco are just set manually looking for faint gray writing in a black background (not the best I know).

So my questions are the following: with the sofware/sensor adjusting colour through the video card's LUT, does it make any difference what mode I chose in my monitor's colour menu? Will one mode have a larger colourspace than another? If so, which setting should I calibrate from?

Is my workflow/colourspace mentined above, correct?
Many thanks!
Title: Colour Space and Calibrating older IBM P260 monitor
Post by: MPatek on January 14, 2009, 12:04:05 am
Tom,
while I am not familiar with the IBM P260 monitor (CRT), my guess is that its gamut is very close to sRGB color space. This will always be the maximum gamut regardless how you calibrate your monitor. The size of the gamut is defined by phosphors that were used by the manufacturer. For CRT displays, available phosphors give you gamut similar to sRGB.
Since you have chosen the color temperature of 6,500 K you at the same time have the exact white point of both Adobe RGB and sRGB color spaces. In my experience, the presets of white points (D65, D50) do not necessarily give you the desired "true" color temperature (6,500K, 5,000 K). So the Expert mode would be more appropriate providing you use a colorimeter and the corresponding software. As you are aware, manual calibration based on subjective judgement of gray or color patches is not reliable way to calibrate your monitor. You want to adjust contrast, brightness, and gains for the RGB guns. If you do not have any calibrating device available, I would use the Easy mode with sRGB preset. If you see a bluish or yellowish tint in whites, I would go for harware calibration.
The workflow sounds correct - I assume that Photoshop is set to sRGB color space. Having no icc display profile, your computer system defaults to sRGB color space as far as the color output is concerned. If your monitor is calibrated to sRGB you have about the right setup.
 
Marcel Patek
-------------------------
http://www.marcelpatek.com (http://www.marcelpatek.com)
Title: Colour Space and Calibrating older IBM P260 monitor
Post by: PeterAit on January 14, 2009, 09:17:22 am
Quote from: Tom H.
Hi I've read much on the topic but want to make sure I have it straight.

I'm shooting in Adobe RGB colour space.
Using Photoshop in RGB and softproofing with the appropriate paper profile for my Epson 2200
Then using that profile in Photoshop to print, with no ICC profile in my printer software

My monitor's colour menu has an sRGB setting, an "Easy" setting and an "Expert" setting
The easy just lets you set the colour space (I chose 6500), the expert lets you set individual RGB guns (bias and gain) as well as colour space, and sRGB has no options at all.

The black level and gama with Monaco are just set manually looking for faint gray writing in a black background (not the best I know).

So my questions are the following: with the sofware/sensor adjusting colour through the video card's LUT, does it make any difference what mode I chose in my monitor's colour menu? Will one mode have a larger colourspace than another? If so, which setting should I calibrate from?

Is my workflow/colourspace mentined above, correct?
Many thanks!

From the various things I have read, you want your monitor at its default settings when you calibrate it - in your case, this would be sRGB. This ensures that the end result is dictated by the calibration process and not by some non-default monitor settings. By the way, 6500 is not a color space but a color temperature. I am still not quite sure how to decide which monitor temperature to use, but 6500 is certainly OK. Your workflow sounds fine, although you don't mention if PS is set to use ProPhoto as the working color space. This is a larger space than AdobeRGB and neither your monitor nor your printer can come close to reproducing all of its colors, but by working in ProPhoto you ensure that maximum color information is retained in your images.

Peter
Title: Colour Space and Calibrating older IBM P260 monitor
Post by: digitaldog on January 14, 2009, 09:42:47 am
Quote from: Tom H.
So my questions are the following: with the sofware/sensor adjusting colour through the video card's LUT, does it make any difference what mode I chose in my monitor's colour menu? Will one mode have a larger colourspace than another? If so, which setting should I calibrate from?

Reset the display to factory default. Then set your software first for a native white point and native gamma, (luminance is based on print viewing, I'd start at about 140-150cd/m2 for an LCD). Try that first. Then see how the soft proof compares to the final print under appropriate matching print illumination.