TUAW has previously reviewed the Padcaster (US$149 or $189 with lens), a tremendously useful tool for mounting an iPad in a sturdy aluminum frame that includes multiple tripod mounts as well as cold shoes for mounting lights and microphones. It's such an iPad moviemaking powerhouse that it recently appeared in one of Apple's "Verse" advertisements. At present, there's no Padcaster for the iPad mini with Retina display, although Padcaster boss Josh Apter currently has a Kickstarter project underway to fund manufacturing of one. For those who have the mini and might not want to spend the bucks for the high-quality professional Padcaster, there's the iOgrapher (US$65).
The major difference between the Padcaster and iOgrapher is in the material used for the frame. The iOgrapher uses black polycarbonate to encase the tablet rather than aluminum. Instead of multiple threaded mounts and cold shoes around the exterior as on the Padcaster, the iOgrapher has three cold shoes for popping on those lights and mics. On the bottom is a single brass-lined threaded tripod mount.