Messing about with channel mixer in B&W

I tried messing about with the channel mixers on a couple of images in rawtherapee. They were all taken on K10D with Pentax-M 28/3.5 at around f11 I think.










Does anybody know of a good tutorial of how to use the channel mixer to modify/enchance B&W and colour images?

Thanks,

Richard

Hi Richard,
Here is a link to a free download for B&W Plus, a very good free conversion plugin for Photoshop.

Link

John

VirtualPhotographer is another great plugin!
(Thanks for the link John )