Did everyone read this notice on the I'm Back" website:
“Note to Professional Photographers: I’m Back was created with the intention
of reusing the old analog in a digital way, but maintaining a “retro” aspect in the
photos thanks to the focusing screen. It is not intended to have the quality of a digital
camera of last generation, therefore, it is not an accessory to be at par with a digital
or even an analog. I’m back gives a unique result in its genre. In similar solutions,
like “Pinhole”, “Lomography” . . ."https://imback.eu/home/How disappointing. Film camears were never designed to be "retro" or "lomo"--the
best ones were as good as Hasselblad or Sindar could make them. And modern film
is way better than film was 100 years ago. View cameras still offer the highest resolution
available in any off-the-shelf camera.
Even pinhole is capable of much shaper photos than most people think (based on their
experience with poorly designed or miniature format pinhole cameras). Nobody
should ever set out to build a bad camera....or digital back.
Phase One makes 100MP backs for medium format film cameras.
The performance of these backs (pixel density, dynamic range and
low noise) exceeds that of the sensors used in most (all--as of 2017
according to Wikipedia) digital cameras.
Phase One backs do things that astronomical cameras do, like cooling
the sensor, that (consumer-oriented) camera companies like Nikon,
Canon, etc. don't bother with.
Phase One certainly could make a back for 35 mm format: the issue is cost.
High quality digital backs are expensive.
I guess it comes down to what's important to the buyer: image quality
or cheap price. But total cost of ownership is far more important than
initial purchase price. I wonder how robustly built and reliable this
"I'm Back" is?
Digital backs are a good thing, since they increase the options available to
photogrpahers and let them use high quality film cameras that last a long
time and are avaiable used at affordable prices--but only if the back is
robust and reliable.