What Lenses to Use When

“What lenses should I use and when should I use them?” I get this question a lot. Especially since many people know I’m exclusively a prime lens user. For those that are new to photography a prime lens is one that doesn’t zoom. It’s one focal length only. However, I think the “which lens” question applies to prime and zoom lenses. Before I get into the details of why I choose the lenses I choose, let me state that there isn’t really any right answer. This IS art after all. Let me also say that I’ll be talking about lens choice generically. I’m not talking about brands or specific models. I am talking about the internal dialog I have when I step into a situation and I ask myself, “what lens do I want to pull out of my bag?”

There are four fundamental lens characteristics I think about when reaching into my bag. Let me describe each one.

• Field of View & Reach – Field of view is how wide and tall you are going to see through the lens. The wider the focal length of the lens, the greater the field of view. Reach is how far away your subject can be and still fill the frame appropriately for your composition. Field of view and reach are inversely proportional (wow… just had flashbacks to Junior High math class). In other words, the longer the reach the narrow the field of view.
• Distance compression or expansion – Distance compression is the optical effect that makes objects in the frame look closer together than they really are. Distance expansion is the opposite, making objects in the frame look farther apart than they really are.
• Aperture or “brightness” – Aperture, measured in “F Stops” determines the amount of light that a lens allows into the camera. Lenses with larger maximum apertures (smaller F Stop number) allows more light to hit the sensor or film allowing the photographer to work in lower light scenarios. Aperture also affects depth of field. The max size of an aperture is often referred to as how “fast” the lens is. The larger the aperture, the “faster” it is. “Fast” really refers to the fact that at the same amount of light, a faster (larger) aperture will allow you to set your shutter speed faster to achieve the same exposure.
• Depth of Field – This is the amount of area in the fame that will be in focus. Managing depth of field can allow a photographer to isolate a subject or on the other extreme get everything in a room sharp. Depth of field is affected by three factors. Aperture, focal length, and distance from the subject. The smaller the aperture, the shallower the depth of field. The longer the lens, the shallower the depth of field. Lastly, the closer the camera is to the subject, the shallower the depth of field.

Next, let’s understand how these characteristics apply to our lenses.

• Normal lenses – For the purpose of this post, let’s say that a normal lens is 50mm for full frame DSLR cameras and 35mm for crop frame DSLR cameras. These lenses are considered “normal” because they see the world very similarly as our own eyes. They don’t really do any distance compression. They have a field of view similar to our own vision. This is also subjective. Many will tell you that normal is a little bit wider or possibly a little bit longer. But we’ll use 50mm as our watermark today. If you are shooting a crop frame camera you can use 35mm as your “normal”.
• Wide angle lenses – These are lenses that are wider than 50mm. For zoom users, you could have a lens that can zoom out wider than 50 and zoom in longer than 50. When you are zoomed out, consider your lens as a wide angle. Wide angle lenses have a “wider” field of view. The shorter the focal length, generally means the wider field of view. Conversely, this means it has less reach. This means you may need to be closer to your subject. Wide angle lenses exaggerate distance (distance expansion) making objects look further away from each other in the frame. Wide angle lenses also inherently have a deeper depth of field. This makes it a bit harder to “isolate” the focus on your subject, but makes it easier to get your subject sharp.
• Telephoto lenses – Can you guess? Yep, lenses that have a focal length greater than 50mm. These are also referred to as “long” lenses. The longer the lens, the narrow the field of view. Inversely, the longer the lens the greater reach it has. This is great if your subject is far away. Long lenses tend to “compress” distance making objects look closer to each other than they really are. Last, the longer the lens, the shallower the depth of field. This makes isolating your subject easier with a longer lens, but can also make getting sharp focus a bit more difficult.

Let’s look at some rather boring photos of my daughter (who was less than thrilled to be my model) that illustrate these characteristics. For each of these photos, I tried to position her eyes in roughly the same part of the frame to illustrate how the different lenses effect the look of the image. For the gear heads, I’m using a Canon 24L, 50L, and 85L as well as a Canon 5d mkII.

First up, depth of field. In these three shots I’m using the 50mm lens. The camera is on a tripod and both the camera and model stay in the same shot for all three images. The only change is the aperture and inversely the shutter speed/ISO to keep the image exposed properly.

In the above image, you can see that there is a very shallow depth of field. Here eyes are even a bit soft. I almost went to reshoot this, but I left it in. It illustrates that while shooting at this small of an aperture can look really cool, you are likely to have less keepers because depth of field is just a sliver. The background is oh-so-creamy though! When shooting this shallow, put a focus spot right on the eye or the most important element of your subject to keep it sharp. One last thing to notice. Every lens has it’s strong points and it’s weak points. Most lenses distort and vignette the worst at either ends of it’s aperture range. As you can see with this lens at f1.2, there is considerable darkening around the edges. I personally dig it, but it’s good to know how your lenses will react at their extremes.

This second images is at f4.0. Model and camera is in the same place. The background is still soft, but not as soft as at f1.2. However, the face is now much shaper. The hair is sharp. At f4.0 there’s a lot more room for error with your focus and still wind up with a sharp image. For people in motion, I’ll usually shoot between f2.8 and f4.0.

In this last of the three depth of field examples, I’m shooting at f11. The tree in the background is only slightly out of focus. You can make out details in the background, trees, and grass. The depth of field at f11 is pretty large on a 50mm lens.

Next, I made some examples to demonstrate field of view and distance compression/expansion. In these shots, my model stayed in the same spot for each shot. However, I shot the first one with a 24mm lens, the second with a 50mm, and last with an 85mm. The exposure and aperture remains the same in each picture. The only thing that is different is that I move the camera for each shot. Just as in the depth of field examples, I try to keep her eyes in about the same spot in each picture.

In the above shot, look at how far away the tree appears behind her. Also notice how much of the road is in the shot as well as the bird bath on the right. The 24mm lens is exaggerating the distance. It even makes her face face look further from her body. It’s good to note that this is not the best lens to use if your subject has a large nose. Wide angle lenses tend to “stretch” objects in the image. The further to the edge, the more stretched they’ll appear. So, a wide person placed near the edge will be made to look wider. So, use wide angles with care.

Look, the tree just got closer to the subject! Not really, but at 50mm this is where the tree really looked to be to my naked eye. The subject is in the same spot. However, I have moved the camera back to keep her composed the same. Notice that we lost a lot of the street and the bird bath is now gone. This is a good way to eliminate distracting elements that are at the edges of the frame.

In the last of these demonstration shots I’ve put on the 85mm at f1.8. Now the tree is right up on the subject, but she’s in the exact same spot as all the shots. Not only is the bird bath gone, but so is the window on the house and we only have a sliver of road left. Much narrower field of view from the 24mm. Facial features are also compressed a bit. 85mm to 200 mm lenses are often used for portraits because the distance compression is very flattering.

One last tidbit to mention. Camera shake! Camera shake is evil. I mentioned that the larger the maximum aperture is, the more light is let into the lens. More light, means you can shoot at a higher shutter speed. Higher shutter speed means the potential to have sharper images (less shake). For me, I try to buy lenses with the largest maximum apertures I can find (warning… they can be expensive). Another thing to consider is that the longer the focal length of the lens, the more camera shake is amplified. As a general rule you should minimally shoot at 1/. So let’s say you are hand holding a 180mm lens (or a zoom lens, zoomed to 180mm), you should shoot at no slower than 1/180th of a second. Twice that (1/360th) if you really want things sharp. There are a lot of aids that can help you shoot at slower shutter speeds like a mono-pod, a tripod, or built in Image Stabilization. Each person is different, though, so practice hand holding at different speeds to determine where your “breaking point” is.

Now that you know the character of your lenses, I’ll run through some typical scenarios. Before I do, I’d like to say that I love my 50mm lens. It’s my go to lens and gets used probably 75-80% of the time. I usually start there and choose something different only when it’s characteristics aren’t working for the scenario. I think every photographer should have a fast 50mm lens in their bag.

A portrait session with a nice, but busy background. In this scenario, I like the general color and tone of a background, but i don’t want it to interfere with my subject. My thought is that I want to isolate the focus to just my subject. This means I want a shallow depth of field. Some factors to think about… The faster the aperture, the shallower the depth of field. Also, the longer the lens, the shallower the depth of field. I may pull out my 50mm f1.2 lens. If the background is still too distracting, I’ll use my 85mm f1.2. Still too much, I may pull out my 200mm f2.8, provided I can get far enough back to still frame my subject like I want.

I need to get a full shot of a dining hall all set up for a reception. For a shot like this, you need a large depth of field as well as a wide angle of view. A wide angle lens would be my choice to fit the whole room in the image as well as maximize my depth of field. I’ll usually reach for my tripod and set the aperture around f16 or greater. With my 24mm at f16, you don’t even really need to focus. Everything is going to sharp.

I was just been told that Madona is going to be leaving her hotel in a few minutes. There’s already a crowd by the front door. You have a close spot, but you are going to have to hold the camera up over your head to get the shot. If I’m close enough, I’m going to pull out my wide angle lens and put the aperture at around f11 or greater if it’s bright enough (or I have flash). Then prefocus your lens in manual to have the to focus around where the front door is. You’ll have a huge depth of field. When she comes out the door, point your camera in her direction and fire away. She’ll be in focus and you’ll be capturing a wide enough field of view that even if you aren’t pointing directly at her, you’re still likely to get the shot.

I’m shooting a senior session down town. I stumble upon a fantastic old door with amazing color. However, the wall surrounding the door is really ugly and distracting. My very first thought is, I need to narrow the field of view. The longer the lens the better in this scenario. A 200mm lens will allow me to shoot my subject and the door only.

A concert venue hires me to get a shot of the audience during a show that they can use to advertise the room for rent. However the night that they booked me had very poor turn out and the room looks fairly empty. If I can focus in on a group and “compress” the distance, it won’t look like there are 3 empty rows between the full rows. I would grab a long lens, get low to not see the empty chairs. The compression will make the rows of people look closer together, therefore more crowded.

I’m shooting a wedding. It’s the scenario and I need to get a shot of the kiss, but I don’t want to be in the way of the guests. This is the perfect scenario for more “reach”, so I grab the longest lens I have and step back to compose my shot.

The wedding reception (or any party) is at full tilt. Drinks are flowing and I need to capture the energy. For me nothing puts the viewer in the middle of the action like a wide angle lens. The wider the better. Fisheye’s work well. Warning… to do this, you have to put yourself into the action. The reason it feels like the view is there, is because your camera was there.

The rings (or other detail shots) at a wedding. It’s hard to beat a macro lens for the little details, but I’ll often use my 50mm as well. Either way, I like to break out the tripod. When you are really close and like to use wide open aperture (shallow depth of field), just breathing can throw the detail out of focus. A tripod will ensure the sharpness of the details.

I want to exaggerate how tall someone is or the size of an area. Wide angle. The wider the more exaggerated. Get close to the subject and angle down (or up) to make the scene stretch out.

I’m shooting a wedding in a dark church. I’m told that I’m forbidden to use flash. In this scenario, I’m going for whatever lens I can get enough light through the lens to get a sharp, properly exposed shot. I have to options: Fast or Image Stabilized. A 50mm f1.2, or f1.4 can be a life saver in these scenarios. f1.2 or f1.4 will usually allow enough light set your shutter speed fast enough to get sharp focus and freeze ceremony action (i.e. people standing relatively still). You can also use an Image Stabilized lens, but they don’t make the shutter any faster. IS (or VR) will usually allow you to get sharp focus, but may not give you a fast enough shutter speed to stop motion.

So, next time you are working a shoot instead of choosing your lens or your zoom factor exclusively on the framing of your composition, think about the other characteristics of your focal length. Visualize in your minds eye how you want the shot to look and then choose your lens or your zoom focal length based on the character you want for the image.

Here’s some real world examples from some of my shoots:

Web:                http://thomaslesterphotography.com

e-mail:             thomas@thomaslesterphotography.com

Facebook:        http://www.facebook.com/thomas.lester

Twitter:                       http://twitter.com/tlester

Written By Thomas Lester

Thomas Lester is a Wedding and Event photographer based in Jacksonville, FL. When he’s not shooting couples and weddings, he’s knee deep into music and local events. Thomas is a self proclaimed geek and loves to share his knowledge openly with others trying to learn their craft.