Aw okay, thanks everyone :)
3D are the pictures and 4D is the dvd movie.
4d is a series of 3d images that's are put together to show movement
My profile pic is in 4D and the best times to see baby in 4D is between 27-32 weeks but you can get it done anytime, depending on where you go. You can actually see more facial features the further you are. I hope this helps a little. :)
3D is close but 4D is alot closer