You may not need a RIP if you print from an Adobe application or other bitmap application that supports direct printing to raster devices. Most Adobe applications can correctly rasterize artwork for bitmap printers (inkjets), except where Postscript effects are being used. The manufacturers of consumer inkjets have drivers that support their model of printer to interpret bitmapped images. However, Postscript or eps images or files will not be printed. Photographers, for most of their work, do not need a RIP, as they can print directly from Photoshop.
InDesign and Illustrator, however, create postscript …