hi, i am doing wide field A confg mapping. i use Imagr with tiling and see a very bright source way off axis. When I tile the mao I get one position for the source, when I don't tile I get a different position (no surprise). which position is the right one to use in UVSUb if I want to subtract the source from the uvdata, ie, does uvsub do it right or not? bob becker