Hi guys and girls,

Any ideas on how to reduce chroma noise only without touching the luminance noise in Aperture 2.0 (a la Canon DPP and virtually every other raw converter)?

i think you can't. this function used to be in A1. haven't seen it since. but the converter improved a lot. if you really still need it switch the rawconverter to 1.1. and the dial reappears.

In the raw section, you can do it through moire reduction.