A crucial concept in photography is depth of field (DoF). All photographers should be able to define DoF and identify the factors that influence it. Many photographers are aware that changing the aperture affects depth of field (DoF). However, did you know that DoF is also influenced by other variables? In this article, I’ll go over the basics of depth of field and how to manipulate it.
1. What is Depth of Field?
When taking a picture, the distance between the subject and the background determines the depth of field. As a result, your camera can now only focus on a single point with accuracy. There is a gradual decline in sharpness, and the term “acceptably sharp” is a relative one. Without going into too much detail, how you view the image and the size at which you view it have an impact on how sharp an image is acceptable. In addition, your vision plays a role!
It’s based on something called the circle of confusion, according to science. Here, I’m not going to get into all the physics! In his article “Hyperfocal Distance Explained,” Spencer discusses the subject. So if you’re interested in learning more about the technical aspects, have a look there.
I’ve attempted to demonstrate the difference between a shallow depth of field (DoF) and a wide DoF in these two sketches. Only a small portion of the image is in focus when taking a picture with a small depth of field (DoF). On the other hand, a wide depth of field brings more of the scene into focus.
2. Why is depth of field important?
Your image’s depth of field (whether it’s shallow or deep) has a significant impact (and can often make or break the composition).
Without a shallow depth of field, you’ll end up with a mediocre portrait with a blurry background that looks like it was snapped with your phone.
A shallow depth of field will make it difficult for the viewer to appreciate the entire scene if you’re shooting a landscape with a stunning foreground, stunning midground, and jaw-dropping background.
In the end, focal length matters. Your photos will improve immediately once you learn how to manage it.
3. Photo Demonstration
The next step is to demonstrate how to alter the depth of field for a specific scene using a few examples. Before I go any further, I’d like to show you the equipment I used to capture the images you’ll see in this article. This should give you a better idea of the scale of the photos and the distances between the various subjects I was photographing. I moved my tripod closer/further away from the props to alter the camera-subject distance. The Nikon D500 was used to capture all of the test images.
In photography, aperture refers to the opening in your lens through which light is allowed to pass to the camera’s sensor. Take into consideration it as a lens’s pupil. While bright, it expands to let in more light, and contracts to keep it out the rest of the time. When it comes to adjusting the depth of field, most photographers start with aperture.
Shallow depth of field is produced by using large apertures, which correspond to low f-stop numbers. Small apertures, or high f-stop numbers, on the other hand, result in images with a shallow depth of field.
Alaska, United States – Focal Length 16mm – Aperture ƒ/13 – Shutter Speed 1/320s – ISO 100
Focal Length 100mm – Aperture ƒ/2.8 – Shutter Speed 1/160s – ISO 250
5. Camera-Subject Distance
The distance between the camera and the subject has a significant impact on the depth of field. The smaller the depth of field, the closer the subject is to the camera. Ever tried taking a close-up photo of a flower or insect, but couldn’t get the entire thing in focus despite using a small aperture? This is because the depth of field (DoF) gets shallower as you get closer to your subject.
Take a look at the following two galleries of images. The distance between the camera and the subject in the first set of images is 1.5 meters. I reduced the aperture after each shot. Nearly half a meter separates the two sets of lenses. There are two things to keep in mind. The depth of field (DoF) increases as the aperture is shrunk in each image. When the camera-subject distance is greater, there is also more depth of field in each pair of photos taken at the same aperture.
I just wanted to drop you a line. There are numerous depth of field calculators to be found on the internet.. DoF mobile apps are also available for download.
6. Focal Length of the Lens
A wider depth of field can be achieved with wide-angle lenses than with telephoto lenses because they have shorter focal lengths (long focal lengths). Actually, that’s not entirely accurate! It’s not as simple as that. This holds true if you don’t alter the camera-to-subject distance when you take the picture. This is demonstrated in the following two sets of images. The photos in the first set were taken at a 70mm focal length. A 105mm setting was used for the bottom. A 2-meter distance separated the cameras in these two shots. If you look at these images taken with the same aperture, you’ll see that the depth of field is greater with the shorter focal length lens.
The comparison between the two sets of images, on the other hand, is unfair. Each collection has a vastly different field of view. More of the landscape can be seen in the images at the top, and the reindeer are much smaller.
I took two more pictures to be on the safe side when comparing the two. The first picture was taken with a 35mm lens at a distance of about 0.6 meters from my focus point (still the eye of the nearest reindeer). I repositioned the camera so that it was 1.2m away from the subject for the second image. With my lens set to 70mm, I framed the shot to have about the same size and location of the deer’s head as the first shot. The depth of field (DoF) appears to be the same in both images. Look at the acorn in front of the deer’s nose and the snowflake and acorn behind the deer’s nose to see this effect. Both images have a similar level of sharpness.
So, what gives these two photos such a distinct visual difference? There are actually two reasons for this. For starters, this has nothing to do with the depth of field of your camera. Unfortunately, the sun had already set when I finished composing and shooting! As a result, the darker background in the second photo must be ignored. Please accept my sincere apologies! Aside from that, the longer focal length has a narrower angle of view than the shorter one. As a result, only a small part of the background is visible. Due to the background’s apparent magnification, the photo taken with the longer lens appears to have a larger blur.
As a result, adjusting the camera-subject distance so that your subject’s magnification is the same has no effect on DoF.
7. Sensor Size
A camera’s depth of field is influenced by sensor size; smaller sensors have a greater depth of field.
However, you must exercise caution when drawing comparisons. For the same field of view, compare cameras that use lenses with the same effective focal length. If you use the same camera-to-subject distance and the same aperture settings, you’ll notice that larger sensors have a shallower depth of field. As a result, full frame cameras are popular among professional portrait photographers. Here’s an illustration of what I mean. Cameras are set to f/9 and a distance of 5.0m between the camera and the subject for all three types of lenses (which have the same field of view, by the way). Each image will have a different DoF, as shown in the table below.
However, a frequently asked question is whether or not similar images can be captured with the same depth of field using cameras with varying sensor sizes. Yes, that’s correct. To get the same depth of field, multiply the apertures by the crop factor. Even if you use the same cameras and lenses as in the preceding example, using an aperture of f/18 on a full-frame camera, an aperture of f/12 on an APS-C-sized sensor, and an aperture of f/9 on a Micro 4/3 camera will result in images with roughly the same depth of field (DoF).
8. Determining Depth of Field
A depth-of-field preview button can be found on many DSLRs. Pressing this button while looking through the viewfinder causes the camera’s lens to close, revealing the final image. However, the viewfinder will become extremely dark when using small apertures, making it difficult to see the preview!
Some cameras’ live view functions allow you to see what the depth of field will look like before you buy the camera. To find out if your DSLR is capable of this, consult the manual that came with it.
Because what they see in the LCD or digital viewfinder is exactly how the photo will look, mirrorless photographers may have an advantage over DSLR photographers when it comes to post-processing.
I don’t think it’s important to obsess over the depth of field (DoF) in a picture. That would be detrimental to the hobby of photography because it would diminish the fun of it. Knowing when and how to create a small field of view is far more critical. The same holds true if you require a wide field of view. The advantage of digital photography is that you can take a picture and immediately see how it turned out on the LCD screen. You can quickly review your image without having to get your phone out and calculate Depth of Field! If you’re not happy with the results, try adjusting the camera’s distance from the subject or the lens’s aperture.
Moving closer to your subject or widening your aperture are two methods for getting a shallower depth of field (DoF). Close your aperture or move away from your subject to get more depth of field. Longer focal lengths can also be used to create the illusion of a shallower depth of field.
You’ll have more creative freedom when you know how depth of field affects your photos. Practicing will help you the most. Spend some time experimenting and getting to know your camera. To get a new perspective, experiment with different focal length lenses, aperture settings, and even moving your feet. Analyze your images to learn more about the capabilities of your equipment. When the time comes to take photos that matter, you’ll be prepared.
FAQs About The Depth Of The Field
Is depth of field equally distributed in front of and behind my focus point ?
No. The DoF distribution becomes more equal as your focal length increases, with one-third in front and two-thirds behind your point of focus.
How will understanding depth of field improve my images ?
The ability to make parts of your images sharp while leaving other parts out of focus is a critical artistic skill for producing stunning results.
How can I set the depth of field precisely for each photo ?
To find out exactly how much depth of field you’ll have with a particular focal length, you can use a depth of field chart, calculator, or app.
Can depth of field be adjusted to get everything in focus ?
Yes. The hyperfocal distance is a concept that must be used; when you focus at this point, you will maximize depth of field and generally keep your entire image sharp.
What is bokeh ?
Japanese bokeh means “blur” in English. In your image’s out-of-focus areas, you’ll notice a noticeable bokeh effect (i.e., in areas beyond the depth of field). A shallow depth of field is best for bokeh, but you can also improve bokeh quality by moving the subject further away from the background.