1 Reply Latest reply on Nov 22, 2010 4:13 PM by MJOrts

    light representation in CS5 with xyY to LabD50 conversion or how ???


      I hope somebody can help me here:


      I want to represent artificial light sources on an Adobe CS5 canvas.


      Artificial light sources are usually described by xy color coordinates and the luminous flux.


      Lets use typical energy saving CFL (compact fluorescent, energy saving) lamps with 20 W


      4000 K lamp: x=0,382, y=0,389 Phi=Y=1200 lm

      3000 K lamp: x=0,457, y=0,416 Phi=Y=1200 lm


      Now lets draw these 2 lamps in CS5 with the aim to illustrate the light of these 2 lamps on the monitor and in the print....and it should look similiar to the real light !


      How to do this?


      I have already tried to convert the coordinates xyY to Lab D50, and choosed also 1200 lm for the reference illuminant D50 and x= 0,346, y=0,359




      4000 K lamp: L=100, a=3, b=22

      2700 K lamp: L=100, a=22, b=56


      Now I make a black canvas = night.


      Next step: 2 circles with these Lab coordinates for representing the lamps.


      Ok..I see that the colors roughly represent the difference between these 2 light sources..but the result isn't bright enough to represent real light.

      It looks more like "pastel painting"


      What can I do to get a real "light impression" for these 2 lamps on the screen?


      May be I need another screen? (I have just a simple Samsung Notebook TFT screen.)


      I would appreciate any suggestions or experiences.