Hi, I am creating a global hillshade file from the GLSDEM. I've mosaiced the tiles into four hemisphere-wide rasters (16-bit signed integer). I am running each mosaic through the ESRI 10.2 Hillshade tool which outputs 8-bit unsigned files. There are 2 issues: 1) The output files are still huge (20GB or something ridiculous). I have tried tif, jp2 and img but none of them help with file size. 2) I'd like to remove or make transparent the non-shaded areas. ESRI directions say to use a reclassify or extract by attribute to separate non-zero values. Thing is, most of the resulting hillshade pixel values are non-zero so not much area would be made transparent by creating such a file. Any ideas? It seems that much of the support documentation assumes you want to use mosaic datasets which I cannot in this case. Many thanks, Christi ------------------------------------------------------------------------- This list (NEARC-L) is an unmoderated discussion list for all NEARC Users. If you no longer wish to receive e-mail from this list, you can remove yourself by going to http://listserv.uconn.edu/nearc-l.html.