I have a Product model and an Image model with a one to many relationship and I'm currently working with the Image model directly in the Product controller, should I be calling the "Image Controller" (that I currently don't have) to handle all of the image stuff? Keeping in mind that the image cant exist without a product.
There is no direct relation between a controller and a model, and you should never create controllers to 'match' your models.
A controller is used to represent routes/pathways through your application.
A model is used to hold persistent data within your database.
Sometimes, when creating a CRUD application, there is a common amount of controllers and models (i.e. Posts, Comments, Users etc). But that is not because of a 'rule' - just the nature of the CRUD application.
A controller could call a couple of different models, and that would be acceptable.