A collimating system for collimating a radiation beam having a first multileaf collimator and a second multileaf collimator configured such that the radiation beam will pass through the first multileaf collimator before passing through the second multileaf collimator, and pass through the second multileaf collimator before hitting its target. The leaves of the first multileaf collimator and the leaves of the second multileaf collimator may be configured to move independently of one another.