What is the Frame and Why Fill It?Here, the frame refers to the edges of your photograph or the edges of the viewfinder of your camera when you are shooting. The advice to fill the frame means to get in close, to make your subject a significant portion of the final photograph.
This advice is articulated in a lot of different ways, most recently in the admonishment to beginning photographers to "Get close. Then get closer." (This particular wording featured third in the recent article The Most Valuable Photography Tips Ever on Digital Photography School. Check it out for some other great composition and photography advice.) As Valerie explains, "Photographers tend to leave too much ‘stuff’ around their subject. The viewer gets lost in the chaos and doesn’t know where to look. Less is often more."
Fill the frame encourages you, as a photographer, to really spend some time thinking about your subject and how best to feature that subject in your photograph. How can you bring forward the details or the patterns or the most critical element(s) of your subject? How does the background add to or take away from the story that you are trying to tell?
A good tip for whether you have filled the frame - does your subject spill out of the frame and beyond the bounds of your photograph? If so, then you are truly beginning to fill the frame.