To adjust the quality of a fractal

1) On the Options menu, click Iteration Control.

2) Increase the Maximum Iterations Per Pixel value.

Changing the Maximum Iterations Per Pixel value causes the fractal to be rerendered. Setting this value too low will cause some points to be incorrectly identified as being in the Mandelbrot set and make most of the fractal window black. Setting this value too high will produce more detailed fractals along the edges of the interior, but the fractal will take noticeably longer to render.