Avoid The Optimum Aperture for The Photography of Women
If you play tennis, golf, or even baseball, then you’ve heard the term “sweet spot.” Whether it’s a racquet, club or bat, professional athletes amongst others, know their equipment has a sweet spot that can help them move to the top of their game. Photography is no different; there is a sweet spot on your camera lens that can make a noticeable difference in your photos, especially when photographing women.
That sweet spot, also known as the “optimum aperture,” is located on every lens you mount to your camera and varies from lens to lens. For most genres of photography, we want to capitalize on that sweet spot so our images are their sharpest, but when it comes to photographing women, it’s better to avoid it because digital camera sensors are too sharp for the feminine beauty I like to capture.
In the old film days we didn’t worry too much about it as film has a natural curvature and when prints were made from slides or negatives, the light from the enlarger would pass through the film emulsion and a cellulose base gelatin material. This “film look” might provide sharp grain when an image was properly captured and the photographer was dead on their focus, but the post-production process “naturally” gave way to a more pleasing image, almost cinematic in character. Unlike film, digital camera sensors are tack sharp from edge to edge when the lens is properly focused.
Similar to HD TV, digital photos will show more tack-sharp detail, and in the case of women’s complexions, regardless of how well the makeup and lighting is done, digital image captures have a higher probability to magnify imperfections in a person’s complexion vs. film. The simple solution, while still focusing tack sharp on the eyes, is to avoid the lens sweet spot and shoot with a medium telephoto lens, or a lens with a higher focal length, but at a wider aperture between the lens’ widest aperture but not higher than f/5.6.
At these lower apertures for most lenses, you’re just shy of the sweet spot. Thus, if you photograph a female model at f/4 on a 35mm camera with a lens focal length of 150-200mm, your depth of field is shallow but your chosen aperture is less sharp. The effect is that you have a natural “optical drop off” of sharpness which helps soften or diffuse the sharpness of the facial skin, especially the cheeks. On the flip side, if you use an aperture of f/8, which is an aperture either at or close to the optimum aperture on most lenses, then your subject’s skin is too sharp in detail, especially photographing mature women.
There are a lot of variables that determine the sweet spot, including front and rear focus, variables in every camera body and lens, focal length, distance to your subject, etc., but as a rule of thumb, most sweet spots reside between f/5.6 through f/11, thus f/8 is the happy medium average. The key in the photography of women is to avoid this area if possible, including if you need to attach a neutral density filter when shooting outdoors.
Lenses are not uniformly sharp throughout their aperture range or at every focusing distance. Focusing distance is related to depth of field and other factors whereas lens sharpness is the actual resolving power of the lens. Lenses in general have a sharpness drop off on both ends of their aperture range. While smaller apertures do bring more of the image into focus through depth of field, the image is overall less sharp then the middle apertures of a lens.
The loss of sharpness at smaller apertures like f/22 is a combination of many factors including how light rays diffract around the actual blades that form the aperture opening in a lens. While overall depth of field improves, lens clarity and sharpness degrade. At these smaller apertures you are also capturing your image through a smaller portion of your lens, in the center, than a larger portion utilized by wider apertures.
A few things to note too, by utilizing longer focal lengths, you also get a more pleasing background that is compressed, magnified plus throw in the wider aperture that avoids the sweet spot, and you’ll get a more mood-pleasing bokeh effect of the background. You’ll also gain a sweeter separation of your subject from the background—and remember, when photographing women, it’s normally about them, not the background.
Wider apertures (f/1.4, f/1.8, f/2, etc.) also allow for more light to strike the camera sensor while smaller apertures (f/11, f/16, f/22, etc.) allow less light; this allows you to use higher shutter speeds at wider apertures. These higher shutter speeds are great for longer focal length lenses as the general rule is too have your shutter speed number match, or even higher, than your focal length due to magnified lens vibrations that can impact the sharpness of your image. For example a 200mm focal length lens requires a shutter speed of at least 1/200th of a second or at least some type of image stabilization (IS on Canon) or vibration reduction (VR on Nikon) mechanism for slower shutter speeds.
Ultimately it comes down to what’s best for your shooting style and genre of photography. There are times I want to capitalize on maximum sharpness of my lens, such as shooting products or landscapes, or even a portrait of a man, but when it comes to female subjects, I’m going try to avoid the sweet spot to use the lack of sharpness as another layer of makeup for my model.
I’m not going to take a tennis racquet to a baseball game or a bat to a golf outing but like those pro athletes that know the value the sweet spot brings to their game, I know how to use or avoid the sweet spot for my photography of women. With that I close and I ask that you don’t forget those who protect our freedoms plus their families and friends. God Bless them! Rolando.