as an expansion on my programs for a singular point mass lens (see my other videos), I've written a procedure to simulate a binary lens consisting of 2 individual point masses (seen as yellow circles).
again, a light source exhibits a linear trajectory on the background (in the source plane), and the light is influenced by the lens masses producing multiple images of the source.

I must note that this animation is of lesser graphic quality than my other animations, because of the fact that the mathematics used vastly increase in complexity with just adding a second point mass. solving the lens equation now comes down to (numerically) solving 5th order equations which, as you may or may not know, are no longer analytically solvable, and as a consequence the images cannot be properly distinguished at all times. this leads to a failure of the 'polygon' command I used before, and therefore it's not possible to give each image it's respective brightness as before (only the total brightness of all images can be given).

so the source is seen as a green circle of dots, while the images are visualized in red.
the dark blue lines are the critical lines, the light blue ones are the caustics.
the yellow circles representing the point masses are not equal in size to represent their difference in mass.
there are usually three distinct images to be seen, but when the source crosses the caustics (light blue), a new image appears, and when the source is fully inside the caustics there are 5 individual images visible.
finally, at the bottom the total brightness of all images is plotted, which can still be useful for microlensing effects, where the gravitational lensing is to weak to distinguish the images optically and only a total brightening of the source is observed. note the brightness has a local peak value when the source crosses the critical lines (which is actually the definition of a critical line).