Very useful...Here are the other formats I could see including if you get a chance, plus some obscure format history. Is there any place where Canon's slightly smaller APS-C makes a difference? Sony sensors (used by most non-Canon cameras) are very close to 24x16mm (varying by a couple of tenths over the years), while Canon sensors are 22.3x14.9.
There are also a couple of other potentially useful sizes, by far the most important of which is Micro 4/3, which is actively developed and sold and relatively popular. Especially because it is the only common interchangeable-lens format (smaller than medium format) with an aspect ratio other than 3:2, it would be very useful to have in the chart.
APS-H was once a fairly common format, sitting in between APS-C and 24x36mm full frame. Most of its use was in Canon pro DSLRs from the original EOS-1D of 2001 to the discontinuation of the EOS-1D mk IV in 2012. Sigma, Leica and Kodak have also made APS-H cameras, although only one slow-selling Sigma model remains in production, almost certainly far outnumbered by older Canon DSLRs still in service and probably outsold by the used market for old Canons.
1" sensors (very close to the old 110 film format) are used in the (mostly) discontinued Nikon 1 system and a number of cameras with fixed zoom lenses, plus many drones. As far as I know, the markings on most of the fixed-lens 1" sensor cameras are actually in full-frame equivalent?
Leica has used a 30x45mm "medium format" with a 2:3 aspect ratio, which has never really caught on, although they have recently announced an updated model with a new sensor.
The sizes above are of at least some practical interest - what's below is in the category of camera geeks only...
In the realm of the truly obscure and probably unnecessary, but sold in the last few years, Sigma has an entirely forgettable "APS-C" format that is even smaller than Canon's, close to midway between Sony APS-C and Micro 4/3. Pentax's Q series has used a couple of different sensor sizes , all smaller than 1".
In the very early days of digital photography, there were even more odd smaller sizes of almost exclusively historical interest... The least exotic were the early Kodak DCS series - the first were smaller than 1" type sensors but larger than the Pentax Q series, while some later models were slightly smaller than Micro 4/3, and a few high resolution models were APS-H. From about 1999 to the demise of the DCS series in the mid-2000s, everything was either APS-C, APS-H or full-frame
Minolta made a couple of exceptionally odd DSLRs with optics in the body that projected light from roughly 1" and roughly APS-C fields of view onto tiny 1/2" sensors. They essentially had built-in Speedboosters... Nikon did the same thing early on, but the effective field of view was 24x36mm full frame. I'm not sure there are more than a few of these early 1990s cameras left functional - maybe no more than there are 12x20" view cameras.
BetterLight's scanning backs aren't really fair, because they don't capture the image in a single exposure - they move a scanner head across the image plane. While they offer the largest capture area of anything sold to photographers today (72x96 mm or nearly 3x4"), there is one way to go even bigger... A BetterLight back is essentially a flatbed scanner attached to a 4x5" view camera, and there is nothing preventing an engineering-minded photographer from attaching a larger flatbed scanner to a larger view camera (admittedly unwieldy in the field).
I think that's all the formats anybody's ever built a digital camera with interchangeable lenses in?
