Popular with cinematographer's, the LL-D Filter was designed to help primarily when using film. It requires no exposure compensation, and makes sufficient adjustments to the film to enable the timer to match the color of a properly 85-filtered original.
It is not an all-around replacement for the 85. Use it only where needed for exposure purposes, and for subsequently printer-timed work. It is used instead of the #85 in low light scenarios since it does not require the 2/3 stop light loss of the #85.