Here is a discussion on my choice of camera by means of looking at some failures of previous attempts.

Hacked second-hand digital cameras:

Originally I tried to hack a second-hand digital camera's buttons and controls to IO pins of an Arduino or Raspberry Pi.

Camera makes I've taken apart in my attempts:

• Fuji
• Sony
• Canon

Of these makes, I found the Canon & Fuji the easiest to open up and work with.

Why this failed / Why this approach was scratched:

• Taking apart a camera risks damaging the camera
• Flash caps! Discharge the flash capacitor!
• Lots of wires and connections where things can go wrong
• Some camera buttons are not as straight forward (mode selection, half press & delays etc)
• Second-hand cameras of the same make are not that readily available

The Raspberry Pi approach

I've decided that using a raspberry pi with python would be a easier approach for me, because I already have the background. For this, I considered the following:

gPhoto:

This project would allow pretty much full control of the camera over USB with some commands. Gphoto is a great option if you already have a secondhand camera that is supported by the package. I decided not to go that direction because of the variability in what secondhand cameras I would be able to find and would prefer to get something pretty standard and reliable.

El Cheapo Webcams:

Easy to integrate into a Raspberry Pi, or network, but usually they are grainy and don't deal with low light very well. The fact that you can pick them up for really cheap, makes it appealing, but the image quality becomes close to unusable.

Better Webcams:

Projects like OpenROV have had great success with decent webcams. I tried sourcing the camera used in the OpenROV project, the Genius WideCam, locally, without much luck. I was told by some dealers that this was considered 'old stock' and will be discontinued in their stores. So considering availability and price, I decided that this would not be the route to go.