first of all - I wish you a happy new year!
After lots of research, I have to say that the Camera situation seems to be dire.
As it stands, there is not a single camera that is:
a) still being made / available
b) supported by CHDK
The last one that was still available in december but is not anymore (talked to canon support today) was the SX410IS.
Sure, one can buy expensive Canon DSLRs, because for them there is the Canon SDK, and i read in many places that not only do they work nice with gphoto2, but Canon offers an SDK for them as well. Unfortunately, the DSLRs are too expensive for most bookscanner-owners. Also the DSLRs have mechanical parts in them that move for every single photo, which leads me to the conclusion that the total lifetime of such a camera is significantly lower then the lifetime of a cheaper, non-dslr "point'n'shoot" camera.
Here is an overview of the cameras that are supported by gphoto:
this overview is nice, because it also contains the megapixel of the camera. if you look through the list, you'll find quickly that not a single one in the list (apart from the DSLRs) is still available.
Here is a different overview, of those that are supported by libgphoto2:
i searched through there and spent a lot of time searching for cameras that are on that list, but also could not find a single one that is available to be bought.
And here is the overview for CHDK:
I linked the "for developer" version of the list, as it contains also the cameras that are currently available, for example the SX420IS, but as you can see from the list, for this camera the original firmware hasnt even been aquired, and so no work has started on portint CHDK for it.
What is the impact of this?
First and foremost, our community, the DIY Bookscanner Community has a big problem, if we can not fix this, as all the nice software (spreads, piscan..) requires the camera to be controlled by the computer.
secondly, the NGO Searchwing (https://www.searchwing.org/), which are building drones to save lives in the mediterranean sea is also desperatly trying to find a camera that a linux computer can control, which they want to put on the drone itself.
I guess many other communitys and NGOs will see the impact of this problem.
What can we do?
I think we as a community need to decide which approach we want to support, I see two options:
I dont know if monetary support is the right thing, but I do also believe, that if we can settle on a camera (for example the SX420IS or the IXUS285, then we can pay someone to develop an integration into either CHDK or GPhoto2. If everyone of us chips in a small amount (5-50€) or so, then i think we can offer a nice payment for porting a current camera.
The upside of using gphoto2 is that it works with most high-end cameras already nicely. The downside is, that most of the current bookscanner software is developed to use CHDK (spreads, piscan). As the last years have shown, CHDK support for a camera might be available, but only becomes available months or years after that camera is already taken off the market and is not being sold anymore - so we need to ask ourselves wether CHDK is the right horse to bet on for the years to come.
I dont know which community is more active and quicker with integrating new cameras, and I dont know much about the hurdles to switch piscan or spreads to gphoto2, which is why i opened this thread.
Lets have a lively and productive discussion how we as a community can solve this problem.