Digital BW, The Print

> From: Steve Kale [mailto:stevekale@...]
>
> Finally got a chance to look at this.  I can use Eye One Share to take an
> ambient light reading of my screen (using Evaluate -> Light) but again the
> results are just given in terms of lux and colour temp.  Basically a 100%
> black square on my monitor is 6 lux measured at the face of the display.
> (The amount of light measured at eye ball distance would of course be less
> according to the inverse square principle.) I have searched the web for a
> way to convert this to Lab's L but most of the hits are very very
> technical
> in nature - way over my head.  I also sent a question to Gretag support so
> we'll see what they say.

Lux is still a linear quantity, so you can still take the log of the ratio
of white lux to black lux, to get the "density" of the monitor.

If you want to know how much the black level measured at the screen surface,
in candelas per meter squared or whatever, is degraded by the screen
reflections, just divide the white level, which isn't significantly affected
by screen reflections, by the lux ratio you measured above.

--

Ciao,               Paul D. DeRocco
Paul                mailto:pderocco@...