In practice, cameras are not great tools for detailed file organization. Even if folder naming were better, doing it on a camera screen is usually slow and awkward.

A simpler approach is to create visual separators while shooting. Before each new set, take a photo of your hand, a written note, or a sign naming the location/subject. When reviewing later, those marker shots make it easy to find where one sequence starts and ends.

For technical experiments, you usually don’t need separate folders at all: aperture, focal length, lens, and other settings are stored in the EXIF metadata. Photo software can later filter or search by that information.

For travel or repeated locations, use marker photos to label each stop, then sort and keyword everything afterward on a computer. You’ll likely want to review and cull images on a larger screen anyway, since judging keepers on the camera display is unreliable.

So the best solution is usually: keep shooting on one card, use marker shots to separate groups, and organize/filter later using metadata and photo-management software.