Focal Length for Portraits: Part 1
Outdoor portrait of young girl with EF 24-700mm lens
By Laura Morita
By: Laura Morita
May 18, 2017
When I was first starting on this journey of photography, I didn't understand how my lens or focal length made any difference to my images. I would see images that I liked and often would try to replicate that look on my own. While certainly many of my early images weren't good because of a huge misunderstanding of how to work with light and how to expose, a lot had to do with not understanding how focal length affects the final look of an image. In this article, you'll learn more about how your choice in focal length has a big impact on the final look of your image.
So, let's start with the basics. What is focal length? The focal length of the lens is an internal optical measurement, defined in millimeters. Lenses are either zoom lenses, meaning you have ability to change the length of your lens (zoom in and out), or they are prime lenses, meaning the focal length is fixed (you cannot zoom in or out). A lens that has a short focal length, say 16mm, allows you to see a lot in the frame without having to step way back. Historically, a “standard” lens had a focal length around 50mm — this would deliver a perspective similar to what our naked eyes see. A lens with a long focal length, say 200mm, allows you to zoom in close from a distance with less being seen in the frame.
In this article, all references to lens focal lengths and their visual effects assume we’re shooting with a digital camera with a full-frame sensor. If you’re using a digital SLR or “mirrorless” camera with a smaller APS-C size imaging sensor, any lens effectively produces more of a telephoto look than its marked focal length would suggest. So throughout this article, if I say I got such-and-such a look with a ___mm lens, divide that number by 1.6, and that’ll be the lens you’d need with a Canon EOS Rebel, 7D-series model, or EOS M-series camera to get the same look.
Just by changing the focal length, you can dramatically change the look of your image. Probably the easiest way to really visualize the difference between different focal lengths is to compare portraits all taken with the same settings (ISO and f/4.0 aperture), but with different focal lengths. For this, we'll use my highly uncooperative son.
As we look through these pictures, take a look not only at his facial features, but also at the background. In all of these photos, I am doing my best to keep the composition similar and my settings the same. As I zoom in and take photos with longer and longer focal lengths, I am backing away from my subject to get the same composition.
Here he is at 24mm. Note the number of trees in the background. There's maybe six or so. His head appears a little distorted.
At 35mm, the background is starting to look a little more blurry, and there aren't as many trees visible. All I have done is step further away from him and zoom in.
At 65mm, the background begins to blur even more, and it looks like there are less trees behind him. He also obviously looks thrilled.
At 105mm, even at the same aperture, we are really starting to see a blurred background, and it's getting hard to even count how many trees might be back there.
At 135mm, it's really gotten blurry in the background, even though the aperture has remained the same. The trees just end up being a blur of color.
For me, discovering that focal length actually made a difference was a huge surprise to me. I was zooming in and out, willy nilly, just trying to get a composition that I wanted and not realizing that my focal length would affect the overall feel of my image. Once I realized the effect that focal length had, I gained a lot more control over the final look of my images.
So, in a nutshell, wide-angle images will show more of the background, and everything will appear more defined. As you zoom in and use a longer focal length, you'll discover that the background will be compressed and magnified, making it appear more blurry and less defined, even when the aperture is the same. If you're taking portraits with a zoom lens and want to get a standard portrait with a blurry background, STEP BACK and ZOOM IN. If I am shooting with the 24-105mm f/4.0L lens and want to blur out the background, I'm going to step away from my subject and zoom in. There's a big difference between a portrait shot at 24mm and 200mm. In the images below, the one on the left was shot at 24mm. Her nose and forehead appear large and distorted. The image on the right is at 200mm. Take a look at her nose in both images and guess which image she prefers?
This is not to say that people pictures should only be shot at longer focal lengths. I have and use many different lenses with different focal lengths, and have come to love the looks that I can achieve with my lenses. I don't use all my lenses in the same way. What works for my 16-35 wide-angle zoom lens doesn't work for my 135mm lens.
So, simply changing the focal length and not even adjusting the aperture can affect the background, making the background appear more in focus (wider angle) or less in focus (longer focal lengths). Of course, aperture also influences the appearance of the foreground and background because of its effect on depth of field. Choosing a lens that has a wide maximum aperture will do a lot to help blur the background, which is often so coveted in portrait photography. One of the advantages of prime lenses is that their maximum aperture can be a lot larger than a zoom lens. Most professional zoom lenses max out at an f/2.8 aperture, which is pretty dang awesome. But with prime lenses, you can get f/2, f/1.8, f/1.4 and even f/1.2. You'll sometimes hear people refer to prime lenses as being faster. This is because when the aperture is larger and allows in more light, the shutter speed can be faster at the same ISO. If you're really wanting a blurry background, get a lens with both a long focal length and large aperture.
A wide-angle lens is considered anything lower than 35mm, assuming you’re using a full-frame camera — you’d need a lens about 22mm or lower to get similar effects with digital cameras having smaller APS-C size image sensors. Generally, wide-angle lenses are not considered good portrait lenses. At ultra wide angles (less than 24mm), most wide-angle lenses will distort the subject, which is usually considered undesirable for portraits. That said, I'm a huge fan of wide-angle shots of kids. My two favorite wide-angle lenses are Canon’s 16-35 f/2.8L (exclusively wide-angle) and 24-70 f/2.8L (wide-angle to standard). I also have the 24-105 f/4.0L lens, which is a great all purpose lens, allowing you to get both wide-angle, standard, and short telephoto images.
I was fortunate enough to get to play with the 11-24mm rectilinear f/4.0L lens. As a huge fan of the 16-35 f/2.8L lens, I was really interested in checking out what it could do. While most wide-angle lenses cause linear distortion (sort of a “fisheye” effect, where straight lines appear curved), this lens causes minimal distortion while still providing a 126 degree field of view at 11mm on a full-frame camera. It's hard to get a sense of what that means exactly, but DANG, I could see SO MUCH through my lens and it wasn't terribly distorted. I'm so thankful my sister happened to take a snap on her phone right when I was photographing my nephew being pretty excited about all those gumballs. Look how close I am to him! The fact that I could stand on the other side of a narrow aisle and STILL get so much in the frame is completely mind blowing to me.
Canon EOS 5D Mark III, 11-24mm f/4L at 11mm
1/200 sec; f/4.0; ISO 8000
This was one of the things that I loved best about this lens. It worked great in small spaces. If you're needing a lens for limited spaces and don't want a lot of distortion, you may want to check out this lens. Here, I'm in front of the TV while my son and brother play a video game. And there's SO MUCH in the frame. Did I mention my mind was BLOWN with this lens?
1/400 sec; f/4.0; ISO 16000
I immediately had to seek out ways to really play with perspective with this lens, and love how it did with emphasizing how tiny a human my little niece is. Isn't she the cutest???
1/160 sec; f/4.0; ISO 200
And while I certainly loved playing with the 11-24mm f/4 lens, I can't quit the 16-35mm f/2.8L lens. In the image below, I used it to capture the story of my son getting ready to jump into the lake. I was standing on the same dock as my son, so I'm fairly close to him. With a wide-angle lens, I was still able to get a lot of the environment in the frame while also showcasing my happy son getting ready to take a dip. Note that the back of the innertube looks much bigger than the front. This is perspective distortion. Items closer to the camera will appear larger and thus, distorted.
Canon EOS 5D Mark III, 16-35mm f/2.8L II lens at 16mm
1/1250 sec; f/4.0; ISO 500
I also love wide-angle because it allows me to get close to my subjects, who are almost always kids. This allows a different type of interaction that can't be achieved if I'm far away from my subject with a long lens. When I'm up close and personal with a tiny human, I can get expressions that I find more difficult to achieve when I'm far away from them. So, when I'm wanting to get that whimsical, inquisitive, silly, expressive face, I grab an ultra wide or wide-angle lens.
1/60 sec; f/2.8; ISO 1000
Another fun advantage of a wide-angle lens is the ability to really change your perspective. You can play with shooting from above, like the next shot, which really emphasizes how little kids can look. This was shot with the full frame Canon EOS 5D Mark III and 16-35mm f/2.8L lens. I was able to get this shot with the camera at my face and just pointed it down at my subjects. I love that I can get this perspective without needing to stand on a stool or something. I do have to be careful to not photograph my feet, but can always remove them in Photoshop if necessary!
1/800 sec; f/3.5; ISO 320
You can shoot down low, keeping in mind that whatever is closest to the lens will appear larger. Use this to your advantage! In this image, I wanted the wheel of his bike to appear huge, so I purposely placed it closest to my camera.
1/400 sec; f/2.8; ISO 400
I love how the distortion of his legs brings some fun and whimsy to the image below.
1/800 sec; f/7.1; ISO 400
A wide-angle lens can be great for taking indoor photos where you might be tight on space. In this image, I'm shoved between the bed and a closet, but am still able to get my darling niece and those amazing guitars in the shot.
1/200 sec; f/2.8; ISO 800
There's just something about a wide-angle portrait that I adore. I find that shooting from above so that the eyes are the closest thing to the camera helps to make the eyes (or glasses!) look bigger and I love the way it looks. It also helps to center your subject when photographing a portrait with a wide-angle lens because there is more distortion noticeable at the edges of wide-angle images.
1/250 sec; f/2.8; ISO 4000
Focal lengths between 35mm to around 70mm are considered "standard" with a full-frame camera. (You’d need a lens between about 22–45mm to get similar effects with cameras using smaller APS-C size image sensors.) As the focal length gets a little longer, close-up images look beautiful without a lot of distortion. The below image shows how phenomenal a portrait shot at 35mm can be. Look at those eyes!
1/640 sec; f/2.8; ISO 400
At 35mm, you can still shoot from above and get a full body image with a full frame camera, but unless you're really tall, you'll probably need to stand up on something. In this image of these adorable twins, I'm standing on a bench shooting down at them.
1/400 sec; f/3.2; ISO 1600
At 35mm, you can definitely still get wonderful environmental portraits, like the next shot of the young lady on a weathered outdoor stairway.
1/500 sec; f/2.8; ISO 500
This image was shot with the 35mm f/1.4L lens. Shot at its widest lens opening of f/1.4, you can see just how luscious the background gets due to the shallow depth of field. So pretty!
1/125 sec; f/1.4; ISO 100
As we move toward longer focal lengths, the 50mm lens deserves a special nod. When I was first starting to understand the effect that aperture had on depth of field, I was absolutely thrilled when I bought the relatively inexpensive 50mm f/1.8 lens. I had been shooting with my kit lens and hadn't yet learned that zooming in would help me achieve a more compressed, blurry background. I had been dying to get that blurry background I so often saw in portraits and using the 50mm at f/1.8 was my first time I achieved that. I was in heaven. I have since upgraded to the Canon 50mm f/1.4 lens, which has even a larger aperture, making it great for shallow depth of field or when shooting in low light conditions. More heaven.
The 50mm lens is the classic “standard” lens, with both full-frame digital SLRs, and traditional 35mm film cameras. It gives a very natural perspective, which differs from the wide and ultra wide perspectives we’ve shown up to now in this article.
The 50mm focal length is a great focal length for close-up portraits.
1/160 sec; f/1.6; ISO 200
1/400 sec; f/1.6; ISO 125
It's also still great for getting environmental portraits. You just have to back up more than with a wider angle lens. But at 50mm, you won't get the potential linear distortion of a wide-angle lens.
1/1000 sec; f/5.0; ISO 400
1/2000 sec; f/1.6; ISO 100
Just as much as I love shooting with my 24-70 f/2.8L lens at 24mm for wide-angle fun and whimsy, I love zooming in with that lens for compressing the background, not worrying about distortion, and getting really great full body and close-up portraits.
1/250 sec; f/2.8; ISO 5000
1/400 sec; f/2.8; ISO 320
1/250 sec; f/2.8; ISO 100
To fully appreciate all the glorious focal lengths, this topic is being divided into two articles. Check out my next article, where we discuss lenses ranging in focal length from 85mm to 200mm.
The CDLC contributors are compensated spokespersons and actual users of the Canon products that they promote.