IMAX is projected on a giant screen, wall to wall and ceiling to floor. And the sound often makes the theater shake. 3D is 3 dimensional on a standard sized screen, where objects appear to be coming out of the screen. Special glasses are provided to view a 3D movie.
Patrick got it right, I only have a little to add: IMAX movies can also be in 3D, but not all movies offered in IMAX are in 3D. I have seen where a few movies have been offered in regular format, 3D format, and IMAX, but not IMAX 3D. If you are seeing a larger than life, action type movie there is no substitute for an IMAX 3D movie. On a side note, the IMAX 3D glasses are just plain uncomfortable. At least you and everyone else who attended will have the same marks on your nose and face!
Yeah what Patrick said!!!
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