QTR-Quadtone RIP

Hello Colin.
I believe that Roy mentioned some time ago that the linearize function
was using L* values for the internal scale, so L*ab should be fine.

Regards,
Duane


--- In QuadtoneRIP@yahoogroups.com, "colingruk" <ColinJConway@...> wrote:
>
> Hi,
> 
> I recently started printing with an Epson 3800 in ABW mode using one
> of Eric Chan's profiles
> http://people.csail.mit.edu/ericchan/dp/Epson3800/abwprofiles.html .
> 
> I used Sergei Antonov's R=G=B 21 step wedge
> http://tech.groups.yahoo.com/group/QuadtoneRIP/files/Tools/ to check
> the linearity of the profile, but it was not linear.  I contacted Eric
> Chan and he advised me that as the DTP20 measures in L* space.  I
> should create a step wedge 21 step wedge in L* space with 5 point step
> increments.  I did this and his profile was then linear.
> 
> I regret I cannot get my head round color management and would like
> advice as to whether I should check step wedge linearity with the
> DTP20 for QTR, for printing with this and other printers, using the
> R=G=B step wedge or the L* stepwedge.
> 
> Thanks,
> 
> 
> Colin
>