does anyone know if it is possible to adjust level of the internal mic on the Canon XA-20 while the external ic is attached and adjustable? How is that done?
The user manual is located here http://gdlp01.c-wss.com/gds/9/0300011399/02/xa20-25-im2-n-en.pdf
On pages 86 and 87 it is explained.
As far as I know, the way most consumer cameras of this type operate… once an external mic is plugged in, it automatically over-rides the internal mic. So any adjustments are aplied to the external mic only as the built-in mic is no longer picking up audio once a mic is plugged into the 3.5mm mic in jack.
However, the XA20 is unique in that it allows two seperate audio channels to be recorded at the same time, so one can be selected as 'external' and the other as 'internal' as per the user manual noted by Ed Merritt above.