When I take pictures of geological stuff, whether it's an interesting outcrop or vibrantly-colored gack in a soil sample, I always keep Grover's "near!" (pressed against the camera) ... "Far!" (running off into the distance) in mind. If you take pictures of an entire core or outcrop, you miss out on the details you need to show. If you zoom in close enough to see the detail you need, then you lose the context. So take both.
This seems simple, but I can't tell you how many times I've missed either the details or the larger context when reviewing photographs. For example, the time we were doing lots of drilling in especially sensitive areas (homeowners' front lawns) and the field crews were under orders to take before and after pictures of the areas to show that we had left everything as it was when we arrived. So what did I end up with? 85 photos of a 2' by 2' square of anonymous lawn. I've also had issues with photographs that were supposed to show very specific stratigraphy differences, except all I had were off-kilter photos of an entire 10-foot core.
Sometimes it's overkill, I agree. Perhaps I didn't need to take a series of 13 photographs for each core box a while back (4 photos per core length, 3 core lengths per box, 1 overall photo). But taking detailed notes and a bunch of photos is way better than driving up to where your cores are stored and digging through 37 80-pound core boxes to revisit an interesting fracture.