Depth of Field, Part III: The Myths | B&H Explora
Note that focal length has not been listed as influencing depth of field, angle lens or much farther with a telephoto lens, as demonstrated in the following chart: . Understanding Depth of Field: How Focal Distance Affects DOF, Visualized The goal of this video is to take all of the instruments of depth of field more telephoto field of view you have, the more balanced this ratio becomes. As the formula for DOF states clearly above, the longer the focal length of your lens So, I am going to use an online DOF calculator to speed up my math and Our goal: a nice shot with an out-of-focus background (more on background blur.
Compare the two following illustrations to see how changing the focal length and aperture affect the DOF of an image. Example 1 Example 2 I'm not going to explain the math of why this happens. All you need to understand are the following general rules of thumb: The wider the aperture, the shallower the DOF e.
In each case I'm focusing on the red guitar. In fact, the DOF extends to infinity in this image. Even the buildings in the background, on the horizon, are in focus. If you want a fancy term to toss around at cocktail parties, when you focus on an object beyond what is known as the hyperfocal distance, you produce a depth of field that extends to infinity in the background.
If nothing else had changed, moving farther from my subject would increase the DOF, but this factor was overwhelmed by radical changes in aperture and focal length. As you can see in the image, not only has the distant background gone out of focus, but even the second guitar is slightly blurred.
If you do the math, the DOF for this image calculates to just over 1 foot. Everything outside of the 1-foot-deep zone around the red guitar will be out of focus, increasingly blurry with distance from that guitar. The mm focal length gives us a tight field of view the relatively wide aperture makes for a shallow DOF. However, both of these factors are offset by moving farther away from the subject. Crunching the numbers tells me that the DOF for this image is just over 2 feet, actually slightly deeper than in Image 2.
Despite the big increase in focal length, the greater distance and slightly smaller aperture combined to give us a wee bit more DOF than in the previous image but still not enough for anything but the red guitar to be in focus.
I can't keep the entire red guitar in the frame any more. And clearly, not only is the second guitar far out of focus, but the distant background has become a featureless smear of color and light. Crunching the numbers tells me that DOF is about 7 inches in this image. How to shoot for shallow depth of field? Finally, focus the lens on the part of the subject you want to direct the viewer's attention.
Shooting with a full frame camera will also produce a shallower depth of field than shooting with a cropped one. Because diffraction will decrease the resolution of your photography and thus will reduce sharpness.
Diffraction puts a limit to the aperture choice. Diffraction is the result of light dispersion caused by the edges of the diaphragm blades in the lens. The smaller the aperture the more light rays are scattered, and more negatively will the photo be affected. Does the typical DoF calculator work for macro photography? You need to take into account magnification. What lenses do you recommend for macro photography?
The following ones are great: In photography, it is used to describe the quality of the blur produced in the out of focus areas of an image produced by a lens.
Depth of field - Wikipedia
Bokeh and shallow depth of field are not the same. What lenses give me a good bokeh? Lenses that will give you bad bokeh: How do I shoot a nice bokeh?
Use a long focal length 50mm or more. Get close to the subject. Focus the lens on the subject you want to be sharp. Put your subject far from the background that you want blurred out. Make sure that there are small background highlights, such as specular reflections or light sources artificial or natural.
Depth of field
William Eugene Smith wisely reminds us that depth of field by itself is just another tool more at our service. So, depth of field is a great tool that you can use to turn your thoughts into real stunning pictures.
But, before we plunge ourselves into the exciting universe of depth of field, let me share a few examples with you I tried to connect Heaven and Hell with a stair made of stars. Focusing at the hyperfocal distance was essential to maximize depth of field. Thus, all the elements in the horizon or further away will be in sharp focus e. The only downside is that you lose depth of field in front of the focus plane. This photo shows the white landscape and, in the background, El Toro — our highest hill.
Twenty minutes prior to this shot, the sky was flat with no clouds. Nothing presaged the twilight of lights and colors that we enjoyed minutes later. Once again, Ansel Adams was on our side. Since the rocks were at a distance larger than the hyperfocal distance The image above includes streetlights, lighthouses, the moon and, at the horizon, Mallorca, the biggest piece of land in the Balearic Islands, to complete a great scene during the blue hour. As it is unique to live a sunset from such a privileged position above the village.
Again, focusing at the hyperfocal distance allowed me to have everything in focus, from the roof adornment located in the foreground to the sun. This is very common in portraits. But it also comes very handy when shooting landscapes, street photography, products, events, close-ups and macro photography. Consequently, all the attention is directed to the eye, which is placed right in the center of the image. The forest brings so many fantastic opportunities to shoot portraits.
Take advantage of it! What else can you ask for? In wildlife photography, you must focus very precisely because long focal lengths produce a very shallow depth of field. The photo was taken from inside a hide. The colors and beauty of the plumage of these birds makes photography an art. I was able to close the aperture because the bee-eater was staying still, which in turn allowed me to have the whole bird in focus! I had to widen the aperture a little bit to reduce shutter speed and, thus, freeze the bird.
In some cases, rotating the POF can better fit the DOF to the scene, and achieve the required sharpness at a smaller f-number. Alternatively, rotating the POF, in combination with a small f-number, can minimize the part of an image that is within the DOF. Effect of lens aperture[ edit ] Effect of aperture on blur and DOF. For a given subject framing and camera position, the DOF is controlled by the lens aperture diameter, which is usually specified as the f-numberthe ratio of lens focal length to aperture diameter.
Reducing the aperture diameter increasing the f-number increases the DOF because the circle of confusion is shrunk directly and indirectly by reducing the light hitting the outside of the lens which is focused to a different point than light hitting the inside of the lens due to spherical aberration caused by the construction of the lens;  however, it also reduces the amount of light transmitted, and increases diffractionplacing a practical limit on the extent to which DOF can be increased by reducing the aperture diameter.
Motion pictures make only limited use of this control; to produce a consistent image quality from shot to shot, cinematographers usually choose a single aperture setting for interiors and another for exteriors, and adjust exposure through the use of camera filters or light levels. Aperture settings are adjusted more frequently in still photography, where variations in depth of field are used to produce a variety of special effects.
Focus point is on the first blocks column. The advent of digital technology in photography has provided additional means of controlling the extent of image sharpness; some methods allow extended DOF that would be impossible with traditional techniques, and some allow the DOF to be determined after the image is made.
Focus stacking is a digital image processing technique which combines multiple images taken at different focal distances to give a resulting image with a greater depth of field than any of the individual source images. Getting sufficient depth of field can be particularly challenging in macro photography.
The images to the right illustrate the extended DOF that can be achieved by combining multiple images. Wavefront coding is a method that convolves rays in such a way that it provides an image where fields are in focus simultaneously with all planes out of focus by a constant amount.
A plenoptic camera uses a microlens array to capture 4D light field information about a scene. Colour apodization is a technique combining a modified lens design with image processing to achieve an increased depth of field. The lens is modified such that each colour channel has a different lens aperture. Therefore, the blue channel will have a greater depth of field than the other colours.
The image processing identifies blurred regions in the red and green channels and in these regions copies the sharper edge data from the blue channel. The result is an image that combines the best features from the different f-numbers, Kay InNokia implemented DOF control in some of its high-end smartphonescalled Refocus, which can change a picture's depth of field after the picture is taken.
It works best when there are close-up and distant objects in the frame. Rayleigh length If the camera position and image framing i. Because of diffraction, however, this isn't really true. Once a lens is stopped down to where most aberrations are well corrected, stopping down further will decrease sharpness in the plane of focus. At the DOF limits, however, further stopping down decreases the size of the defocus blur spot, and the overall sharpness may still increase. Eventually, the defocus blur spot becomes negligibly small, and further stopping down serves only to decrease sharpness even at DOF limits Gibson ,