Employing a “side-by-side” design, there is no beam splitter, so it can stay compact while maintaining IMAX’s 1.9:1 aspect ratio at 4K resolution to each eye. Lenses are swapped as a one piece stereo pair with no need to realign separate lenses as the focal length is changed.
Weighing less than half the weight of rivals, the camera also has a pre-record buffer allowing capture before the operator hits the record button, features especially valuable to IMAX Nature Filmmakers.
To see a featurette of the new camera in a behind the scenes look at the new Transformers as well as the IMAX nature doc, Island of Lemurs: Madagascar, click the link :
>> https://www.youtube.com/watch?v=vBAL5ueqt-s#sthash.AMVeXVcX.dpuf
( source http://www.digitalcinemasociety.org/news/new-3d-imax-dual-sensor-65mm-4k-used-transformers#read )