I bought some Panasonic cameras last year and to make the most of their (nearly) square footage----available sensor resolution---I really should be shooting in the 4:3 format. Anything else crops out useful information. But that seems to dictatorial when it comes to creative composition. And it may explain why, after months of compulsory full format shooting with the those m4:3 rascals I've come to enjoy the 16:9 format. It defies logical good practice when it comes to maximizing image quality but it's weirdly dynamic. You lose the top and the bottom of the frame but then you have to use your brain to make things fit in and make the size and shape make sense.
Last Fall I was doing a demo and the camera I was using at the time was hooked up (wirelessly) to an HD television set. The technicians and I decided to set the camera to the 16:9 format to match the full screen of the television. I shot that way for two full days and now, when I look at the images I shot, I am happy to have cropped different.
I guess it's also an active exercise in learning how to compose for videos and films. All of the cameras I'm using for those disciplines are locked into the 16:9 format. Since I'm traditionally a square shooter it's almost a necessary exercise to see in a new way and to break out of that mould.
Makes my brain hurt a little but it does change the way I see things in the finders. I like the variation.
But....this essay in no way creates of permanent contract for me to only shoot long and skinny. I'll be back to my fat and sassy 1:1 format soon enough.