You could be forgiven for thinking the Canon EOS IX is the "EOS 9", but it's actually the "Eye Ecks". That stands for "Information Exchange", and that's a key feature of one of the last...and shortest-lived...film formats out there, the
Advanced Photo System format (APS for short.)
126 Instamatic, 110 Instamatic, Disc...each were an attempt to give casual shooters an easy-to-use form factor that didn't involve having to thread leaders on takeup spools while simultaneously preventing the clumsy-fingered from putting a thumb through fragile shutter components while loading the camera.
While indeed easy to use, these formats suffered from iffy image quality, especially the 110 and Disc, due to tiny negatives. The APS, on the other hand, had negatives almost the size of regular 35mm film.
The mode dial is relocated to the back of the camera because there's a little hatch on top where it normally would be on a Canon body. You just pop that open, drop the cassette (which has no exposed leader) in, and the camera does the rest.
Higher-end APS cameras, like this one, read and write magnetic data off the negatives, hence "Information Exchange". You can rewind mid-roll, and then reload it and it will advance to the first unexposed frame. It can record other data, like date/time or exposure settings.
All this was made possible by rapid advances in digital technology in the Eighties and Nineties, and those same advances would, of course, also lead to the creation of imaging sensors that would supplant film.
While 35mm film is still being made, APS sank without a ripple in 2011. This means that any you buy today is at least half-a-decade expired. The Fujifilm Nexia D100 I got claimed to have been cold-stored, and seemed to work okay. Colors were a bit muted.
It's a
crapshoot on film, but on the Canons, at least, the APS cameras use standard EF-mount lenses, with a 1.2x crop factor. (This makes the excellent
EF 40mm f/2.8 pancake a 50mm equivalent, BTW...) Similarly, the Nikon Pronea 6i uses Nikon's F-mount. Both the EOS IX and Pronea 6i use a pair of CR123 batteries, which is something kept in ample stock at Roseholme Cottage.
With the discontinuation of the film, the cameras are available for
next to nothing, so it's a cheap experiment.
.