Stock photos can be incredibly helpful to filmmaking students, as they provide a visual reference to help them develop their own ideas and bring a scene to life. There are several ways in which stock photos can be useful for students of filmmaking. 

One of the most important ways that stock photos can help filmmaking students is in the development of ideas. When coming up with a concept for a film, it can be difficult to visualize what the scene should look like and how it should be composed. Stock photos can provide a visual reference for students, allowing them to draw inspiration from existing visuals to create their own unique scene. It can also be helpful for students to use stock photos to get an idea of how specific elements, such as lighting and camera angles, should be used in their own work.

Another way that stock photos can be beneficial to filmmaking students is in the production of their films. Many students may not have the budget or resources to create their own sets and props, so stock photos can be a great way to create a believable scene without spending a fortune. Stock photos can also be used as a reference for students when it comes to costume design and the placement of actors and props on a set.

Finally, stock photos can be helpful to filmmaking students in post-production. Students can use stock photos to create effects such as matte paintings and background plates, as well as to create realistic-looking composites of different elements. This can be a great way for students to quickly and easily add a professional feel to their films.

Overall, stock photos can be an invaluable resource for filmmaking students, providing a visual reference to help them develop their own ideas and bring their projects to life. 

Yes, they are very helpful because you can't afford to buy them and you can't afford to have the gear to make them. Sure, they can also inspire and motivate you.