This equipment group can be printed and mounted to a stand so that someone in a wheelchair with very limited mobility of their hands can still use a digital camera with control over pan, tilt, zoom, and shutter. Most digital cameras have tiny buttons and controls requiring fine motor skills and are not usable by people with hand disabilities (arthritis, cerebral palsy, etc). I created this device as part of a project for a class I was in. My mother in law, who has severe rheumatoid arthritis and has very limited fine motor skills of her hands, tested this adaptive equipment and found she could easily use it to take photos with a Sony digital camera. The controls could be tweaked to work with other types of digital cameras as well. The setup was powered by Arduino Uno. Three microservos (zoom, shutter, pan) and a standard servo (tilt) and seven microswitches were used to bring it all together for electronics hardware. I created a wooden mount box that would fit on a wheelchair tray.
You will need to build or find a mounting system to mount everything together. Different cameras will need a different type of Camera Mount file. A Canon camera is probably the best, because I am told you can wire shutter and zoom controls through the USB port in a Canon camera. I had to use a Sony because it was all I had, so I had to use two servos. It would probably be much simpler with a Canon camera, because two of the servos should not be needed if you can electronically control the shutter and zoom on your camera of choice.
I included the Arduino Uno code file that will control the system.