The Aspect Ratio transformation can be used to create fractals for media with non-square pixels. You should add it to all layers of the fractal. It is available as a transformation in Standard.uxf and as a transformation plug-in in Standard.ulb.
The Aspect Ratio parameter specifies the aspect ratio (height / width) of the final media. The final media is the computer screen or printed poster that will eventually display the fractal. If the value of the parameter is equal to the height divided by the width of the fractal window, no stretching occurs.
For example, suppose you would like to display a fractal on a 15″ x 10″ screen that has a resolution of 400 x 300 pixels. Here, the pixels are wider than tall. You would set the width and height of the fractal window to 400 x 300 to obtain the desired size. Then, set the Aspect Ratio parameter of this transformation to 0.6667 (10″ / 15″).
Most computer monitors and printers have square pixels. In this case, you do not need to use this transformation. If you just want to stretch the fractal, use the Stretch parameter in the Location tab of the Layer Properties tool window instead.