There is no built-in FITS data format reader in IDL, so there is no way to read it directly into the iTools using IDL out-of-the-box. However, there is an open source IDL library that has a FITS format reader for IDL : http://idlastro.gsfc.nasa...o/fits/fits_read.pro You could use this to read the data into IDL, then pass it into the iTools. If you wanted to a more advanced solution, you could also wrap this FITS_READ routine with an iTools custom file reader object class that would allow you to read the data directly into the iTools. An example of this methodology in action can be found here : http://www.rsinc.com/code...k/search.asp?FID=309 - AO