Another cool pattern

This one is a bit strange. I took my Evergreen pattern and and multiplied it by my favorite pattern. Here are the formulas again for those new to the series:

$eq1=atan($x/$y)*cos($y*i)*sin($x*$i)*sqrt($x*$y)/M_PI;
$eq2=(cos($i*$y))*(sin($i*$x))*$i;
$eq=($eq1*$eq2);

Starts of pretty simply:

Shows a little more development:

Then, wham, into the fray:

This must look incredible at 50000 pixels!

Ghost images:

This is worth exploring more.