Getting good sound
 

From day one as a cameraman I've had a problem with sound, which has seemingly come to a head with a recent interview.

I use a Z1, usually have the trim at - 12 db. For this interview I set up a radio tie mic and had the gun mic on the camera so i got two chances for good sound. I aim for the levels at about 2 thirds up. i quickly realized the interviewee is speaking incredibly softly, so i turn up the levels. This picks her voice up better, but it also picks every rustling of her jacket, scratching her nails and theres seemingly a hiss of atmosphere as well from the gun mic. So i move the trim up to 0 db, lower the levels and still the noise through the radio mic is unacceptable. and even the on board mic is picking up her fingers scratching her clothes.

The interview in my opinion is now unusable. I know its difficult just from this discription but does anyone have any tips for such a situation? should i stop trying to get the levels at 2 thirds and just capture her voice clearly. (and bump it up in post?) Any good books on specific audio techniques?

cheers

if you got 2 sources slightly different you can use them to extract voice only.
you need to play with the pas of sound and add or substract until you got voice only.
it is the same way some filters extract music for karaoke from song.
they just try to remove the singer by using left and right chanel.