The best way to start with IDL is presumably with the 'Getting Started With IDL' manual.You can access this by going to IDL Online Help's 'Contents tab page -> User's Guides -> Getting Started with IDL'. Specifically, there is a chapter there called "Images". I am not an ENVI expert, but I would think that the following steps would provide the kind of output file that could be shared with ERDAS: Step 1: Open the ENVI image file in ENVI. Step 2: Select 'File->Save File As' from the top-level ENVI menu. Notice how the ensuing drop-down menu includes both 'ERDAS Imagine' and 'TIFF/GeoTIFF' as options. I would think that either one of those options would open automatically in ERDAS. Step 3: In the ensuing 'Select File for ERDAS IMAGINE Output' dialog, select the file you opened in Step 1 and hit 'OK'. James Jones