Silly CIELAB questions


I am trying to understand some apparently minor points about CIELAB.


What do the asterisks in CIELab* stand for? Do they represent a math function? (Not my best subject, although with explanations I can do.)

On the X-rite CIELAB color chart what is the significance of the 60, 60, -60, -60 clockwise around the circumference of the chart? I realize the grid in the chart is in increments of 2 from 0 out to 60 or -60 but what do the numbers signify? If it is just the chroma, how does the range 0 to 60 relate?

What value is considered the 0 point in the hue? It seems to be a red. Or does this even matter?

What is the best visual 3D diagram of the CIELAB sphere and where can I find it?

If I am allowed I would gladly post an image of the CIELAB chart I am talking about.

Thank-you for your indulgence and time.

The asterisks are to differentiate CIELab* from the Hunter Lab color space, which is calculated differently, and represent no math function.

It would be great if you could post an image of what you’re looking at so we could all see it. Instructions on posting images is here:

You just need to link to your image on a publicly accessible web server, wrap it on either end with the BBC codes
( ) and the ColorForum site will display the image within the thread.