The purpose of these imaginary lines is to see intersection points of the grid, where you can establish the image’s focal point.
The purpose of these imaginary lines is to see intersection points of the grid, where you can establish the image’s focal point. The focal point doesn’t have to be in the middle of the tank, as that can take away from the things around it. A specific mark that anchors the viewer’s gaze first, and then from which the viewer’s eye can glide towards other points of interest, is necessary to create an aquascape that is appealing to the viewer.