35mm adapters are designed for using 35mm still SLR lenses with a video camera. By design SLR lenses have a flipped image but the still camera body has mechanism which will flip it right side up for you but when you use the same still camera lense with a 35mm adapter like M2, Letus etc there is no built-in mechanism in the adapter to flip the image hense you capture an inverted image which you will have to flip in Post.
Another obvious problem is since the image is flipped, it shows up as flipped in the camera's LCD hence if you really want to see an upside image while shooting you need a field monitor which can flip the image for you or you may have to flip the monitor itslef upside down to view the correct image.
