Convert RGB to CMYK and/or CMYK to RGB

Guys please elaborate the most effecient way to converting files from one end to another..

What type of files do you want to convert?

you can convert it in photoshope from image > mode and choose what you need

Add to yours... in A. Illustrator the same - File > Document Color Mode

Convert RGB to CMYK and/or CMYK to RGB
Many graphics software programs give you the choice to work in either RGB or CMYK. These are called "color spaces". Scanners and digital cameras create images using combinations of just three colors: Red, Green and Blue (called "RGB"). These are the primary colors of light, which computers use to display images on your screen. Printing presses print full color pictures using a different set of colors, the primary colors of pigment: Cyan (blue), Magenta (red), Yellow and Black (called "CMYK"). This is "4-color process" or "full-color" printing that comprises the majority of magazines and marketing materials you see every day. At some stage your RGB file must be translated to CMYK in order to print it on a printing press.

The best way to do this is in a vector image using Illustrator. Go to Edit > Edit Colors > Recolor Artwork ... With this tool you can specify which color you want to change. That's perfect.

In Illustrator go to file>color document mode

change to the color mode you want cmyk or rg

In photoshop go to image>mode>choose the mode you want

ok thanks alot sir