(RED, GREEN, BLUE) IS NOT (CYAN, MAGENTA, YELLOW, BLACK)
Your image looks like this
The digital camera captures the image in three distinct colors Red/Green/Blue. If you only need the images for an RGB printer or the web (monitor's see color as RGB) this is sufficient information to get the job done correctly.
Red
Green
Blue
However, if you need to use your image printed conventionally in a catalog or brochure the RGB information must be converted to CMYK and without any color or image detail loss. If the photo had been taken with film the film would have been separated into RGB and converted into CMYK.
When you shoot digital you want to place this responsibility in the hands of a capable professional. We have been involved in making separations for over 25 years and converting our own digital images for the past five years.