So this is practically a digital IMAX camera? Fascinating...
Not really... IMAX is 70mm film rotated sideways and uses the
width of the film for the image
height, versus 65mm which uses the film width for image width, in the same way that 6X9 medium format is rotated sideways compared to 6x4.5. It's the same film, but loads length-way, and as a result 3x as much film has to travel through the camera compared to 65mm to maintain the same frame rate, and 4x as much as 35mm; an incredible challenge.
Concerning the Hasselblad lenses: I was outright stunned when I watched "Batman The Dark Knight" in an IMAX Theatre some years ago (the real IMAX, no digital) and I was even more impressed when I read that Nolan had used Hasselblad lenses to shoot the movie. There are some articles around this on the web. Think it was 50/2,8, 80/2,8 110/2 and 150/2,8 what he had used.
Bluntly speaking, nearly all the 70mm lenses made were re-housed Hasselblad lenses, made to be user-friendly for motion film (same size, gears, smooth aperture, et.al). I doubt anyone wanted to produce lenses specifically for this format as it was far too niche, more so than 65mm.
The Dark Knight was actually a mix of camera systems, so every scene where you see anamorphic distortion wasn't shot in IMAX because there aren't any anamorphic lenses for that size, but 65mm and 35mm do have them. If you watched TDK in an IMAX theater you should have noticed the aspect ratio change throughout the film since IMAX is 1.43:1, while 65mm with 1.25x Ana is 2.2:1 and 35mm with 2x Ana is 2.39:1; the IMAX version of the film ran with all the original aspect ratios preserved.