![]() ![]() Like all smartphone cameras, the iPhone’s camera is just too cramped to get the space it needs for a proper shallow depth of field. Photo: Ste Smith/ Cult of MacĪmong other things, depth of field is also affected 1 by the size of the sensor, the distance from the back of the lens to the sensor, and the kind of lens itself. Sensor size, lenses, the iPhone and Portrait Mode Portrait Lighting can make a movie star out of almost anyone. Unfortunately, that’s not the whole story. The iPhone would be able to take those great portrait shots, with the subject popping against a soft background. If that was the whole story, we’d be golden. ![]() It is highly desirable in a photo, because you can blur a distracting background, and focus on the subject. ![]() However, the background will be blurred (as will anything between the persona and the camera). The subject that the lens is focused on - perhaps a person’s face - will be in focus. See how selective the focus is? Photo: Charlie Sorrel/Cult of MacĬonversely, when the aperture is wide open, like our regular open window, the aperture contributes almost nothing to the sharpness of the image. This is the same view, taken at ƒ2.8, a wide-open aperture. This looks good in a landscape shot, where you want everything sharp. So, when the aperture is small, like the pinhole in our window blind, the image is sharp from the horizon in the far distance right up to the objects nearby. The amount of depth of field is partly controlled by the size of the aperture. The amount of sharpness is called the “ depth of field.” (It might help to use the popular term “depth of focus” to make this clearer.) When your camera focuses its lens on a subject, a certain amount of the image is also sharp in front of and behind this plane of focus. Depth of field I shot this with an aperture of ƒ16. But the size of the aperture still affects the sharpness of the picture. An actual camera uses a lens to focus the incoming light. So you see, while a larger aperture (or hole) lets in more light, it also makes the image more blurred. If you put a sheet of photographic film or paper inside a box, then punch a tiny pinhole in the other end of the box, it works the exact same way, only you can actually record an image. That’s why your regular window-size window doesn’t project an image on the wall. As you increase the size of the hole, the image on the wall will blur more and more. If the image is too dim, or you don’t see one at all, try making the hole a little bigger. This image will be a copy of the scene outside your window. On the wall opposite the window you’ll see an image, upside down and back to front. On a sunny day, cover the windows in a room to make the room as dark as possible. Here’s an example you can try at home: the pinhole camera, or camera obscura. That’s because, when reduced in size, a hole turns into a lens, and can focus the light coming through it. Changing the aperture can have an even bigger visual effect on the image, because it controls how much of the picture is sharp. ![]() Photo: Charlie Sorrel/Cult of MacĪs we saw, a camera’s shutter can be used to control how sharp or blurred a moving object will appear in your photos. Here, even the tip of the nose is blurred. How aperture affects your image Extremely-limited depth of field is great for portraits. These sheets are moved behind the lens to control light levels. Some old cameras have interchangeable metal sheets with different-sized holes punched into them. These aperture blades shift to control the size of the hole. As these blades shift together, the size of the hole changes. The most common aperture design uses five or more blades arranged like in the image below. Just like the iris in the eye, a bigger hole lets in more light, and a smaller hole lets in less. The aperture is a diaphragm inside the lens, the size of which can be adjusted. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |