DEPTH OF FIELD

What is depth of field?

Depth of field (DOF) is a critical concept in photography and cinematography that refers to the range of distance within a scene that appears acceptably sharp in an image or footage. It is determined by the camera’s focus settings and the aperture size (f-stop) used during exposure.

The depth of field is divided into three main zones:

  1. Near Zone (Foreground): The closest part of the scene that is within acceptable sharpness.
  2. Focal Plane: The specific distance from the camera where the focus is set, resulting in optimal sharpness.
  3. Far Zone (Background): The farthest part of the scene that is within acceptable sharpness.

The depth of field can be influenced by several factors:

  • Aperture: A wider aperture (lower f-stop number) results in a shallower depth of field, isolating the subject from the background. Conversely, a smaller aperture (higher f-stop number) increases the depth of field, making more of the scene in focus.
  • Distance to Subject: The closer the camera is to the subject, the shallower the depth of field. Conversely, increasing the distance between the camera and the subject deepens the depth of field.
  • Focal Length: Longer focal lengths (zooming in) tend to produce a shallower depth of field compared to shorter focal lengths (wide-angle).

Depth of field is a creative tool that photographers and filmmakers use to guide the viewer’s attention and emphasize specific elements within a composition. For instance, a portrait photographer might use a wide aperture to blur the background, drawing attention to the subject’s face. On the other hand, a landscape photographer may use a smaller aperture to ensure that the entire scene, from the foreground to the background, is in focus.

Understanding and controlling depth of field allows for greater artistic expression and compositional control in visual storytelling.

Depth-of-Field-Diagram-Select-Focus-StudioBinder

Depth of Field: The Essential Guide for Filmmakers [with Examples] (studiobinder.com)

Humans perceive visual information in three dimensions: width (X-axis), height (Y-axis), and depth (Z-axis). Using the example of a vertically held smartphone:

  • Width (X): 2.64 inches (wide)
  • Height (Y): 5.44 inches (tall)
  • Depth (Z): 0.28 inches (deep)

Depth, represented along the Z-axis, is commonly referred to as z-space. In this case, the depth of the smartphone when held vertically is 0.28 inches, reflecting the measure along the Z-axis.

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Depth of field (DOF) is compared to a hallway with doors placed at specific distances. The area between these doors represents the field, and the distance between them is the depth.

  • In the first scenario, with doors at 20 ft and 50 ft, the DOF is 30 ft.
  • Shifting the second door to the 90 ft mark increases the DOF to 70 ft.

The DOF concept parallels the acceptably sharp zone in photography, where objects within the range defined by the doors are in focus, while those outside this range are not. It’s a practical way to understand and measure the spatial extent of focus in a scene.

wide angle lens, all elements in sharp focus, woman with glasses in the style of the san francisco renaissance, light teal and light white, chinese new year festivities, street style, cityscape

WIDE ANGLE LENS, ALL ELEMENTS IN SHARP FOCUS, woman with glasses in the style of the san francisco renaissance, light teal and light white, chinese new year festivities, street style, cityscape –ar 2:1 –v 5.2

What is the circle of confusion?

The circle of confusion is a measure of the diameter of a point source of light that falls on the focal plane of a camera. It is typically measured in fractions of millimeters. This circle represents a point that is never perfectly in focus, and the size of the circle of confusion is used to assess the quality of a lens. The smallest circle a lens can produce, known as the circle of least confusion, represents a light source in “perfect focus.” This measurement is crucial for evaluating lens precision. By calculating the circle of confusion, photographers can determine the precision of a lens’s focus. When combined with the lens’s focal length, it allows for the determination of the hyperfocal distance, a critical parameter in photography.

Testing the circle of confusion is a valuable method for lens and camera manufacturers to assess focus, especially in determining when a subject is officially out of focus. This test is also useful for evaluating the value and construction of a lens. The smaller the circle of least confusion, the more precise and potentially expensive the lens is likely to be. In general, there is a correlation between the cost of a lens and the size of its circle of least confusion, with more expensive lenses tending to have smaller circles.

What does shallow depth of field actually do?

Shallow depth of field (DOF) refers to an image with a shorter field distance, resulting in a smaller region of acceptable sharpness and a quicker drop-off in focus. This effect can isolate the subject and blur surrounding objects. Filmmakers use shallow DOF to evoke various emotions in viewers, such as severity, loneliness, fear, doubt, beauty, heightened senses, and anger. Planning and shot listing the intended depth of field for each shot is crucial in achieving the desired emotional impact. Filmmakers can mark “shallow depth of field” or “deep” on their shot list based on the visual requirements of each scene.

While a shallow depth of field contributes to the emotional tone of an image, it alone may not suffice for most cinematographers. Many captivating and emotionally impactful shots have effectively employed shallow depth of field, including both beautiful and disturbing scenes. However, to fully convey the intended message, cinematographers should also leverage subject matter, performance, lighting, color, and camera movement. These elements play crucial roles in creating a holistic and emotionally resonant visual experience.

TELEPHOTO LENS, SHALLOW DOF, woman with glasses in the style of the san francisco renaissance, light teal and light white, chinese new year festivities, street style

TELEPHOTO LENS, SHALLOW DOF, woman with glasses in the style of the san francisco renaissance, light teal and light white, chinese new year festivities, street style, cityscape –ar 2:1 –v 5.2

What is a large depth of field?

A large depth of field refers to an image with a deeper field, resulting in a region of acceptable sharpness with a lower drop-off rate. This term can also be interchangeable with “deep depth of field” or simply “depth.” Cinematographers may use these terms to describe shots where a larger area of images remains acceptably sharp. Another related term for this concept is “deep focus.”

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WIDE ANGLE LENS, ALL ELEMENTS IN SHARP FOCUS, woman with glasses in the style of the san francisco renaissance, light teal and light white, chinese new year festivities, street style, cityscape –ar 2:1 –v 5.2

MEDIUM DOF, woman with glasses and a shirt, in the style of the san francisco renaissance, light teal and light white, chinese new year festivities, street style, cityscape

MEDIUM DOF, woman with glasses and a shirt, in the style of the san francisco renaissance, light teal and light white, chinese new year festivities, street style, cityscape –ar 2:1 –v 5.2

How to decrease depth of field

The article explores the three methods for achieving a desired depth of field: adjusting aperture, changing camera-subject distance, and considering focal length. Readers can choose to watch a video by Sierra for practical demonstrations or continue reading for an in-depth explanation of these techniques.

Widening Your Aperture
To significantly decrease the depth of field, open up your lens aperture to a low f/stop. A larger aperture results in more blur in your image or footage, but it also means allowing more light. It’s crucial to understand ISO and shutter speed to effectively balance the exposure of your photo.

Move Camera Closer to the Subject
Closer proximity of the camera to the subject results in a more shallow depth of field, introducing blur to both the foreground and background of the image.

Keep Subjects Far From Each Other
Increasing the distance between the subject and the background significantly reduces the depth of field, providing the image with a sense of depth. This effect is also influenced by the distance between subjects within the frame.

Lengthen Focal Length
Using a longer lens allows for achieving a more shallow depth of field. An 85mm or longer lens, particularly in cameras with interchangeable lenses, works well for this purpose. While zoom or telephoto lenses are effective, they are not mandatory. If a longer lens is not available or affordable, there’s no need to worry; other techniques can still be utilized.

To achieve a more shallow depth of field, you can zoom in to the lens’s maximum capacity. However, it’s crucial to mount your camera on a tripod, as extensive zooming increases the susceptibility of the image to shake.

aijessy_Capture_a_candid_and_personal_portrait_of_a_Filipino

Capture a candid and personal portrait of a Filipino fisherman at dawn, BOKEH, pulling a net full of fish out of the water. Use a Nikon D850 DSLR 4k camera with a 85mm lens at F 1.2 aperture setting to blur the background and focus on the fisherman’s face and muscular arms. The backdrop should be the ocean SHALLOW DOF –-ar 3:2 –v 5.2

What governs depth of field?

Controlling depth of field in your images is crucial for creative impact, and there are various methods to achieve this. Combining multiple methods offers extensive control over your photographs. Two significant ways to govern depth of field are:

  1. Sensor Size:
  • Larger camera sensors result in a decreased depth of field. This occurs because you need to move closer to the subject to fill the frame, influencing the focus area.
  • While it’s not advisable to choose a camera solely based on sensor size, it’s a factor to consider in depth of field control.
  1. Aperture:
  • Aperture determines the intensity of light in an image by regulating the amount of light reaching the sensor or film. It is measured in F-Stops (Estimated) and T-Stops (Exact).
  • T-Stops are often used with high-end cinema lenses when describing light intensity.

Combining these methods provides photographers with powerful tools for achieving precise control over the depth of field in their images.

Aperture-Depth-of-Field-In-Post-StudioBinder

The f-stop number is inversely related to the aperture size: the lower the f-stop number, the wider the aperture. Adjusting the aperture diameter affects the angle at which light enters the lens. Widening the aperture angle by increasing the diameter compresses the field, resulting in a shallower depth of field. Conversely, narrowing the aperture angle by decreasing the diameter expands the field, creating a larger depth of field. Understanding this relationship allows photographers to control the depth of field in their images by manipulating the aperture settings.

SHALLOW DOF

water splash in the style of tiffany glass and gaudi, curated collection, transparent, backlit, golden hour, SHALLOW DEPTH OF FIELD

water splash in the style of tiffany glass and gaudi, curated collection, transparent, backlit, golden hour, SHALLOW DEPTH OF FIELD –ar 2:1 –v 5.2

aijessy_dev_patel_in_a_dhoti_standing_over_a_defeated_tiger_war

dev patel in a dhoti standing over a defeated tiger warrior in a futuristic zaha hadid styled prison octagon like gladiators, god rays and dust, worm’s eye view, intricately-detailed, diffuse-back-lighting, small-catchlight, low-contrast, SHALLOW DOF –ar 3:2 –v 5.2

FOCUS DISTANCE

When you approach a subject closely, regardless of your lens’s focal length, the depth of field becomes shallower. Contrary to a common myth, longer lenses do not inherently provide a shallower depth of field. Putting a longer lens on your camera magnifies the subject, simulating the shallow depth of field you’d achieve with a wider lens when very close to the subject. While it might appear that longer lenses offer a shallower depth of field, in reality, you’re not changing the depth of field but adjusting the perspective by moving the camera closer without physically getting closer to the subject.

If your subject occupies the same space in the frame, the depth of field remains constant regardless of the focal length. The magnification of the lens not only imitates proximity to the subject but also amplifies the blurring effect in the out-of-focus areas of the image.

A futuristic city inside a supermassive hangar, style of frank gehry and zaha hadid, worm's eye view, WIDE ANGLE, DRAMATIC LIGHTING, DEEP FOCUS, movie composition, cinematic color, dramatic angle, warm key light, blue fill light

A futuristic city inside a supermassive hangar, style of frank gehry and zaha hadid, worm’s eye view, WIDE ANGLE, DRAMATIC LIGHTING, DEEP FOCUS, movie composition, cinematic color, dramatic angle, warm key light, blue fill light –ar 3:2 –v 5.2

A futuristic city inside a supermassive hangar, style of frank gehry and zaha hadid, worm's eye view, WIDE ANGLE, DRAMATIC LIGHTING, DEEP FOCUS, movie composition, cinematic color scheme, warm key light, blue fill light
A futuristic city inside a supermassive hangar, style of frank gehry and zaha hadid, worm's eye view, WIDE ANGLE, DRAMATIC LIGHTING, DEEP FOCUS, movie composition, cinematic color scheme, warm key light, blue fill light

A futuristic city inside a supermassive hangar, style of frank gehry and zaha hadid, worm’s eye view, WIDE ANGLE, DRAMATIC LIGHTING, DEEP FOCUS, movie composition, cinematic color scheme, warm key light, blue fill light –ar 3:2 –v 5.2

CAMERA DISTANCE

The physical distance between the camera and the subject, known as camera distance or focus distance, influences the depth of field. Similar to the effects of aperture and focal length, changing the camera distance alters the position of the focal element within the lens, impacting the focus on the subject. Adjusting camera distance is a factor in controlling depth of field in photography.

Depth-of-Field-Focal-Distance-Graphc-StudioBinder

LENS FILTERS

Lens filters, such as neutral-density filters, can be valuable tools for controlling depth of field in specific situations. When facing excessive light but desiring a shallow depth of field without stopping down, a neutral-density filter can be used to decrease light intensity. This allows for appropriately exposed images with the desired shallow look. Neutral density filters don’t alter the angle of light rays entering the lens; instead, they reflect a portion of light to lower exposure. These filters maintain color accuracy and can also reduce reflections in images.

Blur anything and everything

Selective Focus Technique:
Selective focus is a creative technique employed by photographers and filmmakers to isolate a specific subject within a frame. This is achieved by using an extremely shallow depth of field, resulting in intentional and pronounced blurring of the background and foreground.

Effect on Surroundings:
The use of selective focus is characterized by an extreme level of blur in the surrounding elements, effectively obscuring details in the background and foreground. This intentional blur draws attention to the isolated subject, creating a visually striking and aesthetically pleasing effect. The technique is often utilized to emphasize the main subject and evoke a sense of focus and significance.

Selective Focus and Shallow Depth of Field:
Selective focus is evident when an extremely shallow depth of field is employed to capture an image. In such cases, the photographer or filmmaker intentionally keeps a specific subject sharply in focus while allowing the surrounding areas to be heavily blurred.

Light Considerations:
Achieving selective focus often requires a significant amount of light. This means that photographers and filmmakers need to be mindful of the lighting conditions when employing this technique. Adequate lighting is essential to ensure the subject is well-exposed and the desired level of blur in the background and foreground is achieved effectively.

worm's eye view, WIDE ANGLE, DEEP FOCUS, hyper realism with graphical retro 60's music poster of dancing chinese afro funk female dj show in tea house, dragon and tiger motifs, elegant, glowing chinese lanterns morphed into disco balls, candle light, dramatic angle, extreme perspective, diffuse-back-lighting

worm’s eye view, WIDE ANGLE, DEEP FOCUS, hyper realism with graphical retro 60’s music poster of dancing chinese afro funk female dj show in tea house, dragon and tiger motifs, elegant, glowing chinese lanterns morphed into disco balls, candle light, dramatic angle, extreme perspective, diffuse-back-lighting –ar 2:1 –v 5.2

Depth of field for long takes

When filming a long take, it is advisable to maintain a large depth of field. This ensures that more elements within the frame remain in focus. To achieve this, staying wide and using a larger depth of field would be beneficial. This approach helps capture a continuous shot effectively, ensuring clarity and detail throughout the extended duration of the take.