It's no April Fool's joke that I'm dredging up this old post.
I've been away most all the last three month on shoots, but found some time to think more about this. The more I did, the more convinced I am this idea is worth pursuing.
Since the price of sensors keeps coming down, it's only a matter of time before a 36x36 one costs no more than a 24x36 does at present. And, with the mirrorless movement continuing to gain more followers, it likely won't be long before we see electronic viewfinders in pro-level DSLRs. Doing without the mirror will solve one of the problems that has limited what image size we can produce from our cameras, as the current configuration of 35-mm style cameras is pretty much maxxed-out at 24mm in the short dimension.
So, the only remaining significant obstacle appears to be lens coverage. I don't, at least at the moment, expect to see many lenses capable of delivering 36x36mm images without SOME vignetting. But, if we can accept a certain amount of fall-off, I think we've opened the door to many exciting aspect-ratio possibilities. After all, how many times is the final image we REALLY want a square?
Permit me a few moments here to make some calculations. The diagonal of 24x36mm image measures just a little over 43.2mm. I'd like to think every lens that produces an acceptable image for full-frame 3:2 cameras covers at least this, and some a bit more. This would also give us 30.6x30.6mm for a square, 26.9x33.7 for 5:4, almost 25.7x34.3 at 4:3 and, for those of us into panoramic vistas, 19.4x38.8 for 2:1 and 13.7x41.1 at 3:1.
Maybe, what we would really want to see is a sensor that allows us to take full advantage of the optics we've paid some seriously money for. Say one, 45mm in diameter, more or less, since I suspect much of our glass covers somewhat more than it was designed for. And, if it doesn't quite measure up, we can always stretch things a bit with software.