Try not to assume anything about how we use film. I already said we widened the film gates in our cameras and projectors. (boil for 20 minutes and allow 5 minutes to sink in

Never said anything about getting rid of 16:9 or speculate it's longevity. I don't get how you don't understand the use of an anamorphic lens.
We shoot for full CinemaScope on cine or video to be shown on cinema screens. To make a CinemaScope picture you start with a 4:3 standard frame into which the horizontally 2x compressed image is recorded.
16:9 only came into being because TV wanted to get nearer to CinemaScope format to compete with the movies. Eventually we might see both TV and cinema in full 2.35:1 but 16:9 is the first step in that direction.
American cinemas shown non-anamorphic films in 1.85:1 which is a very slim difference to 2:1 Panavision format also used in the states. Perhaps this is why the difference isn't obvious over there. Overall these are technical issues that audiences don't care about. All they want to know is that they are getting the whole picture and that nothing is cropped from top, bottom or sides.
Whether it is 4:3, 16:9 or 2.35:1 is more a concern for the film maker. 4:3 as a format has uses other than any anamorphic applications. There are plenty of genre themes people like to cover in movies that are only right in 4:3. If you get rid of it you'll find entries for competitions might turn up with the sides cropped off. I already mentioned "Seven Shades" which we made in 4:3, whilst the only project we have done this way, it won't be the last and we did commission another group to make a film for us in 4:3 last year. We work mostly with full 2x anamorphic and sometimes with 4:3. We just don't have a use for 16:9.
Most of you are using 16:9 simply because it has become the main format on video. Film Thurso has a nice set of seven 2x lenses and doesn't see the point in stepping back to a format with a narrower view especially on the Caithness landscape.
Whilst I'm sure we will eventually find something to do with 16:9 we can be equally sure that 4:3 will always be with us one way or another because there is just millions upon millions of feet of film and video in that format. Whether the format is used in production is not the point. We have to maintain the playability of the foundling format.
