Yes, it is very common. The light coming from most deep sky objects is very faint. To the naked eye, even through an 8" telescope, the Ring Nebula is just a fuzzy batch of bluish light. You can't see any color. Long exposures bring out the color.
Of course, the larger the telescope you use the brighter an object will appear and exposure times would be shorter. However, nothing ever appears like it does in photographs because your eyes can't take long exposures.
Big research telescopes look at extremely faint objects so they still use very long exposures. The famous "Deep Field" photograph by the Hubble telescope was something like 100 hours of exposure time...in order to pick up the faintest objects in the universe.