hj Loc: Florida

Photocraig

You can download iPhone images directly to your computer via Lightning/USB cable. Newer phones--even more expensive than cameras shoot raw.

I think an increasingly capable parade if iPhones properly exercised by Grandpa will do the job. It is a natural to use and easy to carry, and with a good case can be almost indestructible. Using the phone in bright sun is difficult, but unless he's going for HIGH contrast B&W, he should be doing homework or playing ball when the sun is high. Golden and Blue hours for THAT boy, I say. By the way, as much as I'm a Viewfinder bigot, memorizing the camera's frame makes the viewfinder way less relevant. The iPhone lens is so wide that it's easy to shoot and crop in some situations--and instructive afterward.

Best wishes for as many hours as you can get with the lad. At that age his vision is miraculous, and reveals things you would NEVER notice. Enjoy, and build a great relationship on photography like my dad di with me.
C

flyboy61 Loc: The Great American Desert

The cheapest thing you can find! 4 year olds are notoriously fickle and have no concept of keeping things clean, recharged or neat. This extends to the late teens.

Bob Mevis Loc: Plymouth, Indiana

I think a phone would be fine. Use the charging cable to upload via USB port. It's great to hear of a 4 year old who has that much of an interest in photography.