You may not be planning to make a movie in 29x3 now, but this could be very important for future-proofing your projects. 4k displays are expected to start becoming available to consumers this year, 8k is likely less than 2 years beyond that - and 29x3 is the default ratio for the 8k standard. Imagine how tiny your 16x9 material is going to look letterboxed in the middle of one of these new displays and you can see ow important it is to start shooting with a lens like this as soon as possible.