Cap 3 Squeezing the étendue
When an optical desing is stated, calculating the fundamental limitations that frame the solution is important to establishis the performance goal is achievable. In this chapter, we will think "outside of the box" to discuss a general concep, called étendue squeezing o étendue remapping, wich allows one to find device that solve design problems without solutions if only plane symmetric optics are used, that is, those that contend wiyh the limits of skew invariance as presented in the previous chapter. This concept gives us more degrees of freedom for the design, and allows improving the control of the light beam of an optical system, particularly where thight ligh control is needed due to efficiency and geometrical constraints. This demand is specialy pertinent for applications such us automotive lighting and video projectors.