Speaking of lights, I really wish I'd been able to study light more in physics class. Those high school and college courses seemed to have mostly involved projectiles, which is great for a doodler (you should see my notebooks!) but didn't delve much into light and how it works. Not that I would have come out with any more enlightenment [sorry, couldn't resist] but it would have been fun trying.
Normally a camera's aperture, the opening where light enters, is circular and controlled by a diaphragm that is adjusted by means of a dial. The diameter of the aperture determines how much light gets to the camera's sensor/film; this controls depth of field among other things.
Most of the Lensbaby optics use removable disks with varying sized holes to change aperture instead of a diaphragm. This also controls how much of an image is in focus and how much receives the LB blur.
But thanks to some I-don't-know-why-it-works reason, you can change the shape of the aperture to something other than round and still take a good photograph--with some additional, amazing results.
Any bright spot not in focus takes on the shape of the aperture. LB manufactures a set of shaped disks, but you can make your own, too. I hadn't planned on ever shooting with these but a post on the Lensbaby Addicts Facebook page prompted me to revisit the idea. And I happen to have a wee tiny oak leaf paper punch and one LB optic that would make this effect work... The photos are so abstract because I had to push the lens as far out of focus as it would go in order to make the effect appear to its greatest extent.
I also enjoy the irony that not one of the trees I was photographing was an oak...