![]() ![]() (You can use this effect intentionally to create rays of light around a light source.) Closing the aperture creates greater depth of field but at the cost of defocus and artifact within that range of focus. The small details within the range of focus will begin to blur and light artifacts will appear. The other problem caused by small apertures is diffraction-a bending and scattering of light waves as they pass through the tiny aperture. To achieve proper exposure, a small aperture needs to be compensated with a slower shutter speed, increasing blur, or with a high ISO, increasing image noise. It's not easy: there are always trade offs you have to make to make an image. Remember, the basic job of a lens is to force light through a small, sharp hole. Using a small aperture also creates its own problems. Or, if you focus at a point in the distance, you can get a foreground that isn't sharp. So even by using the smallest aperture, depending on the focal length, you might still be working with a relatively narrow range of focus. Also, the range of focus is not affected just by aperture, but also by a lens's focal length: the longer the focal length, the narrower the apparent range of focus. So by focusing 1/3 of the distance into the scene, something in front or behind or both could still be out of focus, and that something could be an important part of your composition. Even at f/11 on a 40mm lens it's possible to get a background that's out of focus.Ī range of focus might not-and often doesn't, even at the maximum depth of field-cover the whole scene from foreground to background. The combination of that and a small aperture (which increases depth of field) should get most of the scene in focus, shouldn't it? Well, yes. The 1/3–2/3 rule of depth of field says that 1/3 of a lens's range of acceptable focus exists in front of the focal point and 2/3 of the range is behind the focal point. ![]() If maximum depth of field is what you're after, you might be inclined to close the lens's aperture as far as it will go (f/22, for example) and focus 1/3 of the distance into the image. And if your choice is to have maximum depth of field in a scene-as much as possible from foreground to background in focus-you need to understand hyperfocal distance. To maximize the value of autofocus and get what you want in the image in focus, you need to choose the focal point. But there are plenty of situations where autofocus and your camera's programming will not give you the best point of focus or the point of focus that meets your artistic intent. Your camera's programming may override that default by choosing the focal point based on certain algorithms for example, if something like a face appears in your scene, your camera may choose that point as the focal point. Autofocus uses edge or contrast detection to sharpen focus, so if left to choose the focal point for itself, autofocus will choose to focus on the most prominent details in the scene. Autofocus, however, only takes care of one step in composing a focused image: it focuses the lens on the point chosen for it. Modern autofocus is awesome and has removed much of the manual finessing from focusing shots. There are several types of photography where the hyperfocal distance is useful, including: architectural and landscape photography, night photography, street photography, and product photography. If that's a bit dense don't worry, I'm about to unpack it all. By focusing on this optimal point-the hyperfocal point-as much of the scene as is possible for that lens and aperture setting will be in acceptable focus from near to far. The hyperfocal distance of a lens is the distance from the camera lens to an optimal point of focus that maximizes the depth of field in the image. To find the hyperfocal distance, and how this method of focusing works in the real In this tutorial you'll learn why hyperfocal distance still matters in the age of digital, how When you want to maximise depth of field, you need to know how to find and use your lens's optimal focal point-the hyperfocal distance. Just because your camera can focus for you doesn't mean you should let it do everything. ![]()
0 Comments
Leave a Reply. |