How to Focus on Multiple Objects in DSLR Camera?

Can a DSLR focus on multiple objects at once? To understand the capabilities of a DSLR, we need to dive into how it works and its limitations.

Yes, a DSLR camera can focus on multiple objects at once depending on the autofocus mode used and the situation. However, there are limitations to the autofocus system that may make it difficult to focus on multiple objects simultaneously.

But don’t worry, we shall not inundate you with technical parlance. We shall elucidate it in a manner that even your elderly grandmother who employs a flip phone may apprehend. Additionally, we shall furnish you with some sagacious counsel to aid you in concentrating on multiple entities akin to an expert.

So if you’re curious about whether your DSLR camera can handle focusing on multiple objects, keep reading. We promise it’ll be worth your time. And who knows, you might even learn something new that will impress your fellow photography enthusiasts. Or at least give you some fun facts to share at parties (because who doesn’t love a good photography-related party trick?).

Let’s get started and find out if a DSLR camera can focus on multiple objects at once.

How a DSLR Camera’s Autofocus system works

The autofocus system uses a combination of sensors and algorithms to detect contrast and calculate the distance between the camera and the subject. It’s like your camera is a superhero with x-ray vision, except instead of seeing through walls, it sees through your lens and knows exactly where to focus.

Now, let’s talk about autofocus modes. There are different modes you can use depending on the situation. For example, if you’re shooting a moving subject, you may want to use continuous autofocus mode to ensure that the subject stays focused as it moves.

But wait, there’s more! Some cameras even have face detection autofocus, which means they can detect human faces and automatically focus on them. It’s like your camera is a creepy stalker that’s always watching you (in a good way, we promise).

However, there are limitations to the autofocus system. One of the biggest limitations is that it can struggle in low light conditions or with subjects with low contrast. Basically, your camera is like a vampire that needs a lot of light to function properly.

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Limitations of Autofocus in DSLR Cameras

The autofocus mechanism of a DSLR camera is undoubtedly remarkable; nonetheless, it is not without its constraints. Perhaps, the most substantial limitation is that it can exclusively concentrate on one object simultaneously.

Moreover, the autofocus system can be at a disadvantage in dim lighting circumstances or with subjects that possess low contrast. In these scenarios, you might need to switch to manual focus or employ alternative techniques to capture the image you desire.

Situations Where You Might Want to Focus on Multiple Objects

Let us explore some scenarios where it may be necessary to concentrate on multiple objects using your DSLR camera. One such situation could be when you are capturing an image of a group of individuals. You would aim to ensure that everyone in the shot is sharply focused and to achieve this, you may have to employ a technique known as “depth of field.”

Another instance where this could be useful is while photographing a panoramic view. You may want both the background and foreground to be in clear focus, and therefore, it may be necessary to make adjustments to the aperture settings to achieve the desired outcome.

However, what about capturing dynamic scenes such as sports or wildlife? In these fast-paced situations, you will require a technique referred to as “tracking autofocus.”

This technique is akin to a game of tag between your camera and the subject, with your camera continually keeping the subject in focus, and thereby capturing a sharply focused image.

Of course, there are always exceptions to the rule. For example, sometimes you might intentionally want to have some parts of your photo out of focus to draw attention to a specific area.

It’s like playing hide-and-seek with your subject, except instead of hiding, you’re intentionally blurring some parts of the photo. There exist numerous scenarios in which one may desire to concentrate on several subjects using their DSLR camera.

Whether it be capturing a group of individuals, taking a picture of a vast and extensive landscape, or seizing action shots, certain methods and configurations can be utilized to accomplish the intended outcome.

How to Focus on Multiple Objects in DSLR Camera?

Firstly, it is of utmost significance to apprehend the discrete autofocus modes that are at one’s disposal on their camera. As previously indicated, these modes encompass single autofocus, continuous autofocus, and face detection autofocus, to mention just a few.

Let’s talk about a crucial topic for photographers – getting multiple subjects in focus. Don’t worry, I’ll be going out to shoot, but before that, let’s cover some theory.

To start, let’s be clear. I am talking about getting multiple subjects in focus in the same image, not compositing them later.

That would be plan B if plan A doesn’t work out. So, let’s discuss all the important parts of getting multiple subjects in focus, which is really useful when you’re photographing animals with their owners, multiple animals, or in group situations.

First, you need to understand the exposure triangle, specifically relating to the aperture. For those who don’t know, the exposure triangle is the relationship between shutter speed, aperture, and ISO. But I’ll only focus on the aperture for now because it’s the key to getting multiple subjects in focus. You’ll need to know how to compensate for that everywhere else.

1 Exposure Triangle

Now, you might know that I like shooting wide open or close to wide open to get all that blurry background-ness in the image. But you can still achieve that and get multiple dogs in the shot. Here’s how.

I have used a 70 to 200 2.8 Sony GM lens with the Sony A7R III. But, honestly, you can use whatever equipment you want. Just keep in mind that there is a difference in terms of the focal length and how much of the image is in focus.

Let’s talk about the principles of aperture. The bigger the f-number, the more of the image is in focus. So, you can increase your f-number to get everything in focus. But, you also need to understand the implications of relative distances.

To illustrate this, I’ve got two candles here. One is closer to the camera, and the other is farther away. If I increase the f-number to get both candles in focus, the one closer to the camera will still be relatively bigger and brighter than the one farther away.

So, what’s the solution? Use depth of field to your advantage. You can put the two candles on the same plane and get them both in focus by using a smaller f-number. Or, you can use distance to your advantage by making sure that the relative distances of the subjects are similar.

And there you have it! That’s how you get multiple subjects in focus. Just remember to understand the exposure triangle, use depth of field to your advantage, and make sure that the relative distances of the subjects are similar.

2 Use Depth of Field to Your Advantage

I can explain how to achieve a good focus on a subject in a photo using two candles as an example. If the candles are next to each other in a straight line, we only need to focus on one of them to achieve a good overall focus on the image. 

But if the candles are staggered apart, I have an issue because they’re on different focal planes. The first thing to note about this is to try and get your subject as close physically as possible to being on the same line. 

If our subjects are sat reasonably close together and I do have one slightly in front of the other one, I can focus on the front subject and get two-thirds of the depth of field falling behind it. The aperture is manipulated by how close the camera is to the subject, so the further the subject is away from the camera lens, the larger the depth of field that’s going to come across. 

We can also use a longer focal length like 200mm to compress everything in the scene and that includes the depth of field. To set the aperture, we can use a handy little trick which is to set it at how many subjects there are in the scene times two. 

But we also need to consider the distance between our subjects and the background and make sure that the distance between us and the subject is less than that distance to keep the blurry background. An important read, Does Shutter Speed Affect Depth of Field?

3 Examples

I have a much straighter long track this way so dog B is in front by a little bit which is fine, so I focus on the front dog. The front dog’s name is Barnacle, right? Sorry about that. I can show you some images taken from that to give you an idea. Let’s zoom in to 200 percent. 

Here I have focused on Barnacle and baby Bryt. Baby B was slightly in front of Alf in this situation, and she’s mid-flick of a head around here, but I’ve got all of her head in focus and all of his head in a nice, sharp focus. 

This was shot at f 4.5, nearly Alf. This is obviously how he feels about being sat next to that dog. I am at f 4.5, and I’ve got a nice, sharp focus across the board. Even with these examples that I’m showing you, just raw files from the two of those two sets together, loads of those images are in focus. 

To achieve this, I used the f-number times two for the subject and moved them close together where possible. Let’s say, for example, you can’t get them to sit close together because they hate each other or they’re just annoying or they can’t do it, and even leads won’t work. 

What do you do then? Well, in that situation, you photograph one there, and you photograph the other one there. Then you composite them together, or when they’re sat side by side, you move your focus point whilst they’re still in position from one to the other, so you’ve got a sharp image of both of them. 

That’s how you photograph two subjects or more in a scene and make sure they’re in focus in one shot. I hope this was helpful. If it is, please let me know and let me know what you think about anything else in the comments below. I’ll see you all again really, really soon.

Conclusion

A camera equipped with a digital single-lens reflex (DSLR) can identify and focus on multiple subjects in a particular scene. However, it may not always be able to maintain the same focus on all subjects at once.

Despite this limitation, certain techniques like focus stacking and adjusting the aperture can aid in achieving the intended outcome. Comprehending the constraints of a camera’s autofocus system empowers one to make more judicious decisions when it comes to capturing an ideal shot.

Don’t be afraid to try different techniques and settings to see what works best for your specific situation. And remember, sometimes even the best-laid plans can go awry, so don’t be afraid to embrace the unexpected and go with the flow (or focus).