You might have to check the camera for DPI/PPI settings and change the resolution of JPEG format from 72 to 350.
However, you can change this in Photoshop by going to Image > Image Size.
It's the metadata (file info) that the camera generates and the ppi figure is for print, not screen.
If you go to Image > Image Size and uncheck Resample, you can change that number from 350 to whatever you want and see the resulting Print Size in English.
I don't know how you set that figure in your camera.
Resolution is metadata in the file, usually put there by whatever creates the files.
If there is no resolution metadata, Photoshop assigns 72 ppi just as a more or less arbitrary default. Photoshop needs some resolution figure to calculate font sizes and smart objects, and 72 is as good as any other number.
Thanks for all the responses. It's a complicated topic asked on many message boards and this is the first time there was an answer that made sense. Many helpful people spend a lot of time explaining resolution and why it usually doesn't matter, which is really great. What always baffled me is how those default numbers got there in Photoshop based on the camera. This seems to explain it.
Again, thanks to everyone.