Does he have an ipad? There are numerous options for very cheap which allow manual camera control and even audio. Let me know and I'll compile a list.
Hi. I think your original camera/SD card idea is good !!
I'd get one with a decent size display and an easy scroll button to review the photos ... just as an example, Nikon Coolpix S3600. They take plenty of abuse and retail for about £70. A simple video program or a dedicated stop-motion program can string up your photos.
No doubt your boy will run into technical difficulties but websites like this will help.
Animating without a computer is certainly a viable option though. Everything I animate, professionally and unprofessionally, I do by using the camera display.
If you decide to buy a camera instead of a webcam, one thing that makes a huge difference is shooting with a wireless remote so to avoid disturbing the camera every time your boy take a shot. Here is one dead cheap but obviously it will have to match the camera you end up buying.
These days you can definitely get a decent webcam for stop-motion for way under $200. Here are some full stop-motion kits for kids; many are bundled with software, camera, and pieces to animate, and they're all under $100.
If you do get Stopmotion Explosion, let me know how you like it.
The thing is, to see what you are doing, you do need a camera attached to a computer. And that is how a webcam (the cheapest suitable camera) works, it sends it's image to a computer. That way, you use a framegrabber program (like Stop Motion Pro, Dragonframe, Monkeyjam etc) which shows you the live view from the camera, and lets you click back to the previous frames you have already then to see how much you have moved your puppet. I started in the old days shooting on 16mm film with no framegrabber, and trust me, you learn so much faster, and get better results and encouragement from seeing what you are doing.
An iPhone or iPad can be used for stop motion with a free or low cost app. But they have automatic exposure, so the pictures keep getting brighter or darker as it adjusts to the animator going in front of the camera to move the puppet. And you have to touch the device to take the photo, which is likely to move it. But it would certainly work for practice.
Any digital camera could be put on a tripod, and you could take shots and save them to the camera's own memory card. Then download the images to the computer later, after you are finished. It wouldn't tie up the shared computer for hours that way. But without seeing how the animation is going, it won't be as good.
Slightly older computers can sell for a fraction of their original price, as newer faster ones come along, so I would look at getting another computer.
You are right, Steve.
This thread dates back to 2014, and since then I have tested a stop motion App on my iPad. It allows you to lock the focus and exposure, so it stays steady. I believe you can even use an iPhone to control the iPad so you don't have to touch it, but I found that mine was steady enough it didn't move around with the light touch needed to take the shot and check the previous frames. As a tool for learning to animate, it was just as good as the DSLR and Dragonframe setup I use, and far better than the 16mm film camera with no video assist that I first learned on. With the right lighting it can produce some pretty good images, though with my setup (based on lighting for DSLR with a longer exposure) I was getting slightly grainy images.
My test is here: https://www.youtube.com/watch?v=pCldXEMOCLM