As for why I’m Back Film uses a Micro Four Thirds sensor instead of a full-frame sensor, the team behind the product says it comes down to cost. A Four-Thirds sensor offers “excellent image quality at a more affordable cost compared to a full-frame sensor.” Further, as mentioned, when combined with a wide-angle lens filter, users can achieve the same field of view on their lens as they would have when using a 35mm camera sensor."
As someone with a bunch of 35mm equipment, this concept is appealing to me, but why not also offer a full-sized sensor at a higher cost for those who want one? This product will always cripple the camera so it's no longer WYSIWYG. The viewfinder will no longer represent what the photo will look like, even with the "wide-angle lens filter" attached. Yeah, when you add their magnifier (what it should have been called) the CCD sensor will "see" the same area that normal 35mm film would see without it, but the photographer will continue to see a larger viewfinder frame than the CCD will see. This makes it a non-starter for me.
Does anybody know of a similar product with a full-size 35mm sensor?