This is part of the reason I can't get in to reverse engineering. It takes an incredible amount of time to get a little done when in the same time you probably could have written your own camera firmware. I do remember seeing an open source camera but it was a really high end one and very expensive.
I really like what they are doing, but they have been working on it for 4 years and have no users. The camera costs 6000 euros and has no internal recording capability.
There exists (or DID exist, before Google snatched up Marc Levoy and made the Pixel cams) open source cameras.
Levoy called the academic exercise he pursued the Frankencamera. (Look it up, a big thing at Stanford). Nokia took him up on it and produced an OTC "smartphone" ... before the iPhone.
i still have a N900 and it works: replaceable batteries do wonders!-) Runs unix etc. Open source camera software.
I remember this, very cool. His team at Google is really at the forefront of computational photography (HDR+, Halide, lightfield photography). Kari Pulli from Nokia also did some very cool stuff on array cameras/computational photography at Light since then.
I think it would actually make sense to build an open source camera on Android. The android camera HAL and camera2 APIs are pretty good (though limited). You get all the UI stuff for free, and a large dev ecosystem. Halide is great for very fast processing. We used them both for the Ubuntu Touch camera app. Though if you really want to push what's possible, access the more low level features would need to be open source too.
Nokia (or HMD Global) are back in the camera phone game again btw - 5 lens android camera coming out this year according to rumours. I think this type of multi-sensor camera really is the way forward on mobile phones. You can keep the lenses thin with much larger sensor size when combined. I really wish they would open source at least some parts of it, but unlikely
Proprietary BLOB's bound the openness of any digital camera. Sensor and chip manufacturing is proprietary and patent encumbered by default. For business agility and cost if for no other reason.
Open source cameras exist. They use chemical processing and have manual controls. The documentation is good and it is even practical to build one's own gear...indeed there is a long tradition. Hacking a Leica film camera just wouldn't be as newsworthy.
In some sense, the low returns smell like an XY problem. To a first approximation, reprogramming a Leica is not going to improve it as a photographic tool. The limitation is the going to be the photographer not the software. For software, there's always post.
The interesting thing about "open-source cameras" in the sense of film is, the film chemistry and film coating methods are very much trade secrets.
Making up developer from base chemicals (metol, phenidone, hydroquinone, and so on) isn't impossible and some people do it so they can "tweak" the process a little bit.
The one thing I've never heard of anyone doing is making up a photographic emulsion from scratch at hobbyist level and coating a film base with it.
I don't disagree. Commercial film stocks tend to be proprietary analogs to BLOB's. Though, for current film stocks, tooling (IDE analogs) for developing those film stocks are available (e.g. C41 and E6). Film stocks requiring proprietary development processes are gone from the market.
There are also well documented photo-chemical substrates that are relatively easy for a radically open source photographer to hack on, e.g. wet plate collodian and the more film like dry plate silver gelatin processes. Not all that practical adapt to a 35mm film camera. But analogously open source jumps through hoops to run on an iPhone.
