Sorry, my PC cannot type chinese now, crazy. 2I@d=T{K
:]rb} 1nLB
I saw some Japanese engineers use "primary differential and second differential" to define the extended freeform optical surface tolerance. 4!</JZX~$
I guess it define some vatied range for each coefficients but I don't know Japanese words. J\@W+/#dF
Still cannot know how to do that.