Here's Albrecht's "4x Symmetrical Mandel" made with his multifractal_12 (MFR) formula: My comments on, and links to, his image and PAR file: The fractal's outer red ring reminds me of a crater wall. The shading of the inside of the crater wall makes the floor of the crater appear deeper than the top of the crater rim. Additional, smaller diameter, interior red rings' floors appear even deeper. The final, black Mandeloid figure in the center must be very deep indeed... A subtlety I discovered -- despite my initial incorrect impression -- was that the fractal does not have perfect left/right symmetry, although it appears that it does have symmetry about its horizontal, central axis. https://bit.ly/50205C04-GIF The fractal's PAR file has Albrecht's multifractal_12 formula included: https://bit.ly/50205C04-PAR - Hal Lane ######################## # hallane@earthlink.net ########################