When shooting models, lighting almost always casts shadows on the subject. If direct sunlight is too intense, those shadows become particularly pronounced. To keep the camera’s shutter speed within an appropriate range, professional photographers typically use apertures with a maximum aperture of at least f/2.8 or wider to allow ample light. With such a wide aperture, the available light is usually sufficient.

　　In addition, the aperture can serve a second purpose: it allows for an extremely shallow depth of field, enabling you to focus attention squarely on your subject while rendering the background softly blurred. On a single‑lens reflex camera, this effect is readily visible through the viewfinder. Meanwhile, to produce brighter, more vivid images, you should set the lens aperture to a relatively wide setting. This way, when you press the shutter, the camera will capture the image using the preselected aperture value.

　　However, a lens hood alone isn’t enough to ensure that the background in every shot is sufficiently blurred. This is because, as long as the focal length is close to infinity—indicated by “∞” on the camera—all objects within the infinite range will appear sharply focused in the image. Therefore, when photographing a model, the photographer needs to maintain a considerable distance from the subject. Furthermore, to achieve the desired effect of a wide aperture, a telephoto lens is also required. In model photography, an ultra‑telephoto lens with a focal length of 300mm or longer is typically used.

　　In portrait photography, it’s also important to distinguish the subject from the background. However, in this case, a focal length of around 85mm is usually sufficient. This is because, compared to model photography, portraits typically only require capturing the head and upper body. Of course, you can also get closer to the subject to achieve the same effect.

　　1. Methods for Achieving a Blurred Background If you want to create a photo with a blurred background, you can do so using one of the following two approaches. 1. When shooting in daylight, simply shorten the exposure time. For example, reduce the shutter speed from the original 1/60 second to 1/125 second; this allows you to open up the aperture by one stop, such as increasing it from f/5.6 to f/4.

　　2. When shooting with a flash, the shutter typically needs to be synchronized with the flash. However, to reduce the amount of light reaching the image sensor, you can also use a neutral density filter, which blocks some of the light from entering the sensor.

　　Close-up: When shooting portraits, a focal length of around 85mm can blur the background. F/5.6 is ideal for portrait and travel photography.

　　When traveling, tourists often photograph landscapes, buildings, or urban scenes. These subjects can draw the viewer’s eye thanks to stark contrasts in brightness within the frame, making automatic exposure modes on a camera ill‑suited to the task. To achieve optimal aperture settings, professional photographers typically work with a range of apertures. They first switch to manual mode and set the aperture to a mid‑range value. Then, they take multiple shots, adjusting the aperture up or down each time. If the resulting images still fail to capture the full spectrum of lighting, post‑processing in Photoshop becomes necessary. Arrange the photos sequentially, then use masks to fine‑tune underexposed or overexposed areas. When shooting distant landscapes, you can no longer rely on a blurred background—especially when emphasizing fine details. For news photography taken while traveling, it’s important to include the surrounding audience in the scene, so the image should ideally avoid any blurry elements.

　　Taking group photos with multiple people also requires depth of field. Portrait mode is ill‑suited in this situation, as the camera’s automatic settings tend to open the aperture wide. At a 50mm focal length, apertures between F5.6 and F8 can easily deliver sufficient depth of field, ensuring that everyone in the shot remains in focus. If you switch to a longer focal length, you should either further stop down the aperture or move farther away from your subject to increase the depth of field.