Joakim,

For understanding:

- ECIrgb has some advantages in highlights and midtones (barely visible for normal printing processes)

- ECIrgb has some trouble with shaddows and darker colors (3/4) which are visible, but often

  superseeded by wrong separation settings on CMYK printers. They will be visible when using

  direct RGB printing processes like those being used for diapositives.

- ECIrgb, like other RGBs with gamma, have trouble to reproduce neutral grey, as it is allways interpolated

LStar-RGB has the same colorspace but tries to correct the problems stated above

- neutral grey is defined in the profile. There is only little interpolation involved

- It has more details in dark tones and shaddows with a barely visible expense in the highlights and midtones

  (RGB 127:127:127 is 50% in LStar-RGB but 60% in ECIrgb)

- It's internal structures are closer to the way how color management software does it's magical math.

  This way there is less guessing and more prediction.

For practical work:

- Both LStar-RGB and ECIrgb deliver better performance than AdobeRGB and sRGB when printing in Europe.

- You will notice differences in output only when the whole color workflow is using professional color management

  at a high quality level. The differences will be superceeded by other printing issues when color management

  and printing is not handled professionally

The issues you experienced before might be due to a wrong setup of your printer (like sending LStar-RGB,

but using ECIrgb in the printer...)

Hope this helps

Karsten

P.S.: Markus, thank you for your help to solve this

Am 31.05.2005 um 11:54 schrieb Joakim Eskildsen:

Karsten,

Thank you for your answer,

I understand that the colorspace betvien Lstar-RGB and ECI-RGB are the same and that Lstar-RGB has a LAB linar kind of gamma and ECI-RGB has a gamma of 1.8, but what I don´t understand is what is meen in practis. I have made some pictures with Lstar-RGB and printed them out on and Ink-jet printer and it somehow looks like they pictures are less colorfull than the monitor. When I make the pictures in ECI-RGB the prints comes out more true to the sceen. 

My cersern is to find the best possoble RGB colorspace for 16 bit editing, (color negatives scanned with imacon 949) the pictures are to go to a exhibition and shall be made on epson new ink-jet printer 9800 aswell as they shall be printed in a book using ISO coted profile. 

Few month ago I used adobe 1998 colorspace for everything but I understad that this ECI-RGB is better designed for the CMYK convertion and for ink-jet colores and decided to use ECI-RGB as my only RGB color space but now I am a bit unsure. 

I can understand from Guenter Bestmann writing that ECI-RGB is the best RGB space conserning printing on Ink-jet and for the CMYK wourld? 

--------------

Joakim Eskildsen

Karlbergvägen 9

02400 Kyrkslätt

Finland

ciao.joakim@dnainternet.net

+358-9-2216 330 fax/ phone

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