  We present a new technique which brings a substantial increase of the
wave-vector $q$-resolution of triple-axis-spectrometers by matching the
measurement wave-vector $q$ to the reflection $\tau_a$ of a perfect crystal
analyzer. A relative Bragg width of $\delta/Q \sim 10^{-4}$ can be achieved
with reasonable collimation settings. This technique is very useful in
measuring small structural changes and line broadenings that can not be
accurately measured with conventional set-ups, while still keeping all the
strengths of a triple-axis-spectrometer.
