Use turbo mode and press the green flag to start. Once your fractal is done rendering, crosshairs will appear and will follow the mouse around. Choose a place in the map you would like to zoom in on and imagine a small square around it. Press space once in the two opposite corners of that square. The pen will then redraw your zoomed-in-on area and you can go through the same process to zoom in again. This fractal theoretically has no limit to its magnification, but the greater your zoom is, the more iterations you will need to make it look nice. Press R to redraw the current zoom location (if you want to see what a different # of iterations looks like) Press Z to zoom all the way out to the beginning Use the up and down arrows to change Iterations beyond the slider limit of 50, but be warned that higher iterations can become VERY SLOW.
You can try running this on Phosphorus to make it go a TON faster and therefore make it less of a pain to zoom in really deep: https://phosphorus.github.io/#261102079 The math behind this involves something called the Mandelbrot set, which takes a bit more explaining than I can do here. Check out these links for more info: https://simple.wikipedia.org/wiki/Mandelbrot_set https://www.bowdoin.edu/~dfrancis/askanerd/mandelbrot/