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Blog Home Filmmaking Film Gear Choosing the Right Lens for Filming an Interview

Choosing the Right Lens for Filming an Interview

Shooting an interview is commonplace for all types of filmmakers. In this tutorial, we run through what focal lengths work the best for almost any setup.

If you’ve just landed your first interview gig but you’re not quite sure what focal length to choose, you’ve come to the right article. While an interview may appear very simple to the viewer, there’s still so much that goes into filming an interview, and it can be pretty overwhelming.

Today, we’re going to focus on the lens choice, and for the sake of this article, I’ll be referring to a camera with a full-frame sensor. That way, when I mention a particular focal length—say, 24mm—the corresponding field of view (FOV) will match that number. I should also mention that though this info is a good starting point for filming interviews, it is by no means the be-all, end-all source for selecting focal lengths.

I am also focusing on a one-interview talent composition in this tutorial. However, as you film more interviews and become more aware of focal lengths and their characteristics you should probably break away from these standards to evolve your art (and blow your client’s mind.)


Intro to Focal Lengths on Lenses

Before I run through the fundamentals on what focal length to choose, let’s quickly recap some basic information on lenses.

Image via bogdandimages.

Lens manufacturers identify a lens’s focal length in millimeters (e.g., 24mm.) The lower the number, the wider the focal length. For example, a 16mm focal length gives a wider field of view than a 24mm lens. Focal lengths are generally grouped into three major categories; wide-angle, medium, and telephoto.

Wide Angle Lenses

Wide-angle lenses are great for establishing shots to give the viewer context of the scene. Typically, these lenses are 35mm and below.

A very standard wide-angle zoom lens is the 16-35mm. In the example shown here, this establishing shot gives the viewer context of a being in ample peaceful space for meditation while also establishing the motivated light source (the fire).

Additionally, if you are filming an interview in an office building, a wide-angle lens would be a great option on a gimbal to capture an exterior shot of the building and an interior shot of the space to give the viewer some context to the environment.

Wide angle lens used to establish the scene. Image via “A Life of Discipline.” Director/DP: Tyler Edwards.

While wide-angle lenses are great for establishing shots, they are not the most flattering for interviews depending on the camera’s position. That’s because they can distort the face and create an unflattering angle. In the example shown here, you can see how the 16mm lens distorts my face compared to the 50mm lens, which is a medium focal length.

16mm and 50mm lens comparison.

Medium Lenses

Medium lenses, such as a 50mm lens, are closer to how the human eye sees images naturally. Every lens kit should include a 50mm lens. The great news is that most camera brands have a very affordable 50mm option, sometimes being one of their least expensive lenses. These are commonly referred to as the “nifty fifty.”

Telephoto Lenses

Telephoto lenses are an obvious choice for wildlife and sports. They allow the photographer to capture the scene with a closer perspective, while still maintaining a safe distance from the subject(s). Telephoto lenses—70mm and up—are great for getting a more intimate perspective on a subject, as a telephoto lens magnifies the image more than a wide-angle lens. Telephoto lenses also compress the image much more than a wide-angle lens.

F-stop

All lenses have an f-stop value. This is the number that corresponds to how wide or closed the aperture of the lens is.

In the simplest terms possible, the lower the f-stop number is, the wider the aperture is. The wider the aperture, the more light hits the sensor. Consequently, a lower f-stop will have a shallower DoF (think blurrier background) than a higher f-stop value.

You may also encounter a lens with t-stop values, which is more commonly found on cinema lenses, but for the sake of this article, we will stick with f-stop.


F-stop comparison at 50mm.

Now that we have a general understanding of focal lengths and f-stop, what should you use when filming interviews? Well, that depends on how many cameras you have. Let’s break that down for 1-3 cameras (I will use a mock interview setup to demonstrate):


1 Camera Interviews

One-camera interviews are not ideal, but sometimes we are in situations where certain constraints on a project limit us to one camera. If I only had one camera, I would select a 35mm or 50mm with a slight bias towards a 35mm.

35mm

Now, this is very subjective, but for me, a 35mm lens is a great focal length for interviews when you want to show the environment surrounding the talent. That wider field of view will provide context as to where the interview is. A 35mm gives a little room for the frame to “breathe” to show the viewer the environment. And with a wider aperture, you can still isolate the subject from the background to make them “pop” in the frame.

Sample image shot with 35mm lens on a full frame sensor.

Additionally, having a wider starting point, I can punch in on the talent in the edit to fake a second camera angle if needed. It is important to record in a higher resolution than the deliverable so that you have those extra pixels to use to punch in to keep the image nice and sharp.

50mm

I absolutely love 35mm, and in many cases, I opt for that focal length. But, there are times when 50mm is more appropriate.

50mm (again, on full-frame) is very close to how we see life every day. That said, when I walk into a location and like what I see from where I want to film, I’ll go straight to 50mm, as that will be the closest to what I see.

Sample image shot with 50mm lens on a full frame sensor.

Likewise, if I am in a location with little visual interest (think dull conference room or bland office space), I will lean towards a 50mm lens. This will compress the background more than 35mm, but still give a “normal” look and keep the camera relatively close to the talent, which is great for filming in spaces with little visual interest.

The power of zooms

This is the ah-ha, the catch-all, the fall-back caveat here. If I only had one lens going into a shoot blindly (DO NOT recommend), I would bring my trusty 24-70 f/2.8. This lens is my secret weapon and I use it on every single shoot because of its versatility—especially for interviews.

It is very sharp (so sharp that I often use diffusion filters in front of it) but provides the flexibility of zooming in and out to be able to fine-tune that FOV precisely without having to move the tripod.

This has saved me many times after the lighting has been set up and the client asks to see how it would look a little wider (or tighter). Especially as a one or two-person crew, making minor focal length changes with a zoom lens is a significant time saver! For those of you on crop-sensor or Super 35 cameras, the Sigma 18-35 is a fantastic option.


2 Camera Interviews

This is probably the most common number of cameras on an interview shoot and is where things get more fun. This is my recommendation as a minimum when filming interviews, as you can cut between the two angles to make an edit feel more seamless. The same rules apply here as with one camera, but there are some considerations and more freedom creatively.

A-Cam

The A-cam is your primary camera. As a general rule of thumb, you want this to be your “wider” cam. This helps establish the environment for the viewer, which is helpful to orient the viewer but also can be very important to the story.

Unless there is a specific reason because of location, generally, I prefer not to go any wider than 24mm, but no tighter than about 50mm for this angle if I am in a location that (1) has the need for establishing and (2) has a visual interest in the background or has enough space and depth to add visual interest with set design.

B-Cam

This is your secondary angle and is sometimes used as a “safety.” We use this angle for reasons such as when we need to cut out an awkward pause, give the viewer another perspective, punch in on the talent during an impactful part of the story, or help with the pacing of an edit when we don’t have to support b-roll in a particular time in the edit.

For the b-cam, I typically start with the “2 times” method, which is simply multiplying the a-cam focal length by two. So, if our A-cam is at 35mm, I would set my b-cam to 70mm.

I prefer to follow this method because you don’t want to have both cameras have a similar field of view. When cutting between two cameras that are 24mm and 28mm, for example, the cut will feel awkward, look too similar, and feel too much like a jump cut, thus defeating the purpose of a b-cam.

I think the two times method is beneficial. Of course, you can go tighter if the client/director likes it or the story calls for it, but I would caution against going wider unless there is a good reason for it.

As for the placement of the b-cam, I typically will either set it a bit offset from the A-cam or go more extreme for a profile shot (both upstage from the talent) depending on the shoot/client preference.


3 Camera Interviews: Adding a C-Cam

For the a-cam and b-cam angles, I follow the same principle as a two-cam setup. This gives me two solid options for cutting between these two cameras during an edit.

When I opt for a 3rd cam (or the client requests three cams), I use the C-cam on a dolly system, such as a Dana Dolly, at either a wide-angle or telephoto. If the location is interesting enough, or the talent might be visually engaging with their surroundings, a wide-angle on a dolly can be a compelling and engaging shot. It can also serve as a “breather” to the viewer during a more extended interview or as a great establishing shot.

Conversely, if I have the A&B cams closer to each other, I like to use the c-cam with a telephoto lens (somewhere between 85mm-135mm) to get a profile shot (either handheld or on a dolly system). I can then instruct the cam op (if I am not op’ing) to be creative with composition and camera movement to help move the story along.

Maybe it is a tight parallax shot, handheld framing of the talent’s nose to the edge of the frame during a part of conflict during the story, or grabbing close shots of the talent’s hands and moving up to their face while they are talking.

Of course, these all depend on the story being told, and these types of shots should be planned out as best as possible in pre-production with the client.


Matching Depth of Field

I mentioned f-stop at the beginning of the article for several reasons. One reason is that if you are on a wider lens, setting your lens at a lower f-stop (wider aperture) helps blur the background more, which helps make the talent pop. When using multiple cameras in an interview, one thing to consider is the depth of field, or what many of us think of as the background blur.

Something that can often be overlooked in interviews is matching the DoF. Many times [I am guilty of this as well], we focus on matching exposure and using the aperture of the lens to adjust. If we use the same f-stop value on a 35mm lens as we do on a 70mm lens, the background blur will be significantly different. The 70mm lens compresses the image much more, thus appearing to have a blurrier background.

Example of the background difference between 2 focal lengths at the same aperture. The background difference minimizes when adjusting the aperture. 

For example, if our a-cam is at 35mm at f/2.8, about 4′ from the talent, and our b-cam is at 70mm, about 6′ from the talent, we would need to set our aperture to f/6.3 to match the background blur. There isn’t a quick way to calculate this.

Still, with a formula I found online: DOF ~= 2 × d² × F × c / (f²), a little work in a spreadsheet to start playing with numbers and an online DoF simulator as a sanity check, I’m able to get a general idea of focal lengths/distances/f-stops to find a good starting place. From there, I check the monitors on the cameras to see if the background out-of-focus bits look similar.

Focal length demonstration. Image via Fouad A. Saad.

I would argue that in most cases, it doesn’t have to be exact. Still, having them similar will certainly be less noticeable when switching between camera angles.

But wait! Since we have different f-stop values, how do we match exposure?

That’s where Neutral Density (ND) filters come into play. In our example, f/2.8 and f/6.3 are 1 and 1/3 stop different, so I would compensate with a 1-stop ND filter first and check exposure and adjust from there. Sometimes lenses at the same f-stop value might not translate to the same amount of light hitting the sensor, so there may be a slight variation in light. That’s why using exposure tools such as false color is so useful.


Selecting focal lengths for interviews is a significant decision that can significantly impact the story. As I mentioned earlier, this article is a great starting place for choosing focal lengths, but it is by no means the final answer. Filmmaking is art, so if other focal lengths in different setups look better to you [and/or your client], then certainly go for it!


Feature image via True Touch Lifestyle.

Looking for more articles about shooting gorgeous interviews? Check out the list below!

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