Did you ever notice that they used soft filters when shooting the female characters on Star Trek and clear lens for the men? Yeoman Rand was beautiful but the filters made her look even better. It just wasn't fair to a boy going through puberty. I am sorry to hear of her passing. One more to beam up, Scotty. Be gentle to this one.
In those days, when a female was to be the only person in a shot, the directors usually used a special soft focus lens. This technique is different than the filtering that's used today. The soft-focus technique has been around since the earliest days of movie making.
The lenses contain quite a bit of spherical aberration in their design, and they softened the "hard" edges of a woman's complexion. Take a look at movies from the "old days", especially in black and white, and the look is especially noticeable. Even the most beautiful actresses of the era, used the technique. You can't get the true soft focus using filters, since they're located in front of the lens, and the needed distortion needs to be in the glass elements.
Men, on the other hand, wanted that manly look, and a few wrinkles here and there added to their maturity. You can also notice that when a man and woman were in the same shot, the soft focus lenses weren't used, since men tended to be the major stars, and women tended to be in the secondary roles.
I used one for a long time when doing studio portraits of women in their forties, and up. They always appreciated it.
