Legend requirements are different for raster grids then feature data types. The raster/grid legend options are weak, and need more advanced capability. The color ramp for grid rendering needs to be displayed and labeled much better. And for contour lines derived from grids, it is crucial to put the contour increment in the legend.
Note: this request has been on the PUG List for many years, currently at
http://www.pugonline.org/index.php?q=raster-legendThis is a quick summary, and I will gather and post additional information in subsequent Comments to this item.
For additional information, eMail
Rich@Priemere.com