A DSLR on a stable tripod is the best choice because you can keep the camera position, angle of view, and exposure more consistent. Use the same exact location and framing every day, and avoid changing focal length; a fixed lens is ideal, or keep a zoom locked at one setting. A tripod with a quick-release plate helps remove and remount the camera without shifting the setup.

Before starting, check the full range of sunrise positions over the term so your frame is wide enough to include the Sun at both ends of its movement. Include a fixed landmark in the scene to make alignment easier and to help restore the setup if it gets bumped.

Use exposure settings that keep the Sun distinct from the sky, and keep those settings consistent as much as possible.

For merging, Photoshop is a straightforward option: load the images as layers, align them using the landmark/horizon, then blend or mask so the Sun from each day appears in the final composite.

An alternative is a solargraph/pinhole approach, which can record the Sun’s path over a long period in a single project, but for daily student photos the tripod-mounted DSLR method is the most practical.