CCD-lab clarifications and some IDL tips UPDATED 9.11

Hi everyone!

After a couple of emails and going through the lab text again I have some remarks and pointers with regards to the CCD-Lab, as detailed here. I put these in a pdf since they got quite long for a simple message, but I wanted to convey some detail to avoid confusion - let me know if I managed to confuse you anyway!

Please read them, as they may clarify some  questions you may have.

Update 09.11: A comment on whether or not to use central region in computations has been added, as well as tips on finding indices for min/max values in matrices.

Cheers,

Ainar