Since I am one of those photographers with no “off” switch, I have a camera with me pretty much all the time. At work, that’s obvious, since taking pictures is my job. But it’s that way for me at home, too.

One of the cameras I sometimes grab at home is my very old Minolta DiMage 7i. I often keep it hanging on a nail next to my computer as kind of a “grab cam” for times when, for example, fleeting sunlight comes through a vase in the kitchen window. It’s right there, and, because of its age and condition (well-used), I am not at all concerned about getting pasta sauce on it or having a dog knock it out of my hands.

It’s got an ace, though, that a lot of newer cameras, by virtue of their lenses, don’t have: a straight seven-bladed aperture. Lensmakers in the latter day have gotten into their heads that everyone wants every lens to exhibit “good bokeh,” and that making lenses with curved aperture blades instead of traditional straight ones is the way to do it.

I was also thinking about all this last night as my wife and I watched the closing ceremonies of the Winter Olympics in Sochi, Russia. The event was quite spectacular, and to enhance the look, the stadium featured lots of spotlights. Television likes to exploit these lights to enhance their visuals.

The real question is: why do we use sunstars, and how do they help us express our vision? Our audience typically sees our images either printed or on a computer monitor of some kind, and the brightness values of these display methods are limited. As we view the scene we photograph, our eyes see all the values, from the darkest shadows to, in many cases, the brilliance of the sun. Since prints and monitors can never express this brightness range, it is then up to us to use photographic elements to express them.

The formula is pretty simple: even-numbered aperture blade produce that number of sunstar points (eight blades, for example, give eight points), while an odd number of blades gives twice that number of sunstar rays (nine blades make 18-point sunstars.) The television cameras at the Olympics, and most television cameras, had six-bladed apertures, so all the spotlights were rendered with six-point sunstars. Now that you know this (if you didn’t already) you won’t be able to look at television again without counting the sunstar points.

Sunstars, at least in my own photography, help me express to the audience the sense of brightness of the brightest items in my image, and the sharper and more beautiful the sunstars, the more my viewers will understand and appreciate my message.