Focal Length

If you use a zoom lens, I don’t mean to pick on them, but they are one of the easiest ways to unintentionally goof up a good photo. That is, unless you understand the effect that focal length has on the look of your photograph, and then consciously make your lens do what you want it to do. That is what I plan to show here.

I have seen or heard two common mistakes with respect to focal length, and yes I used to be guilty of both of these.

1) Stand there in front of something you want to take a picture of. It is either too close, or too far, so you zoom in or out to fit the subject in the frame the way you want.
2) Stick with one focal length (or one prime lens) for everything that you shoot, and move your body to get your subject sized the way you would like.

Before I say both of those are a mistake, I would like to say that many professional photographers can and have done a great job, and put together a great portfolio while violating number 2 above. Usually though, doing so does not cover a wide variety of photographic topics. For example, there is no way I could personally take business portrait, and then turn around and get a desired landscape shot using the same focal length.

Instead of arguing whether or not you can acceptably get away with one focal length, let’s just get on with the point of what focal length does for your photographs, and then you can decide for yourself what will work for you.

Let’s start with example 1 above. If I am too close to my subject and I zoom to a wide angle, it is true that I can get my subject about the same size in the frame as if I were to use a longer focal length, and back up. Subject is the same size in the frame…..what is the big deal right? It is important to understand what your selected focal length does to distances between your subject and everything around it.

For simplicity sake, I am going to break focal lengths up into 3 ranges. Wide angle, normal, and telephoto. I say keep it simple because we could get into moderate telephoto, telephoto and the same with wide angle. Let’s keep it simple and stick with the 3 ranges and understanding what they do. Once you know that, you can tweak in things with the in-between ranges.

Normal

Normal is given that name, because everything appears “normal.” Meaning that the separation between objects is pretty much the way your eye sees things. Some people love shooting with a normal lens and some people call it boring. It all depends on what you are doing.

To understand why it is “normal” you have to understand what the other two ranges are doing for you.

Wide Angle

Focal lengths in the wide angle range produce something fancy called “perspective distortion.” It is distorting the perspective because it is exaggerating the distance between two objects. Simply put, wide angle makes near things seem nearer and far things seem farther.

The classic example of this is the dog nose photo.

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The dogs nose looks as big as its head. Since we see things through “normal” eyes, we know this is not the case. Yet this is the perspective that the wide angle lens is seeing.

This is important for a lot of reasons, but I will cover a couple here. First, if you are taking photographs of people, unless you are going for a specific point, or something artistic, you want to avoid perspective distortion. Meaning you want at least normal, perhaps telephoto, depending the shot (more on that later). Nobody wants to look like the dog in the photo. Yet, people do it all the time!!!

I can’t tell you how many photographs I have seen where a person is posed on the ground, or sitting, and the pose is such a way that their leg is about a foot in front of their head. Nothing wrong with that, but then the photographer stands on top of them, and in order to “fit it all in” the frame, a super wide angle is necessary to take the picture. The result is the person’s leg from foot to knee looks 3 times larger than their head, and their head is this dinky tiny little thing in the back. And I see people wanting to charge money for that all the time. Don’t make that simple mistake!

I don’t care if your lighting is perfect, posing is otherwise great, exposure is spot on, if you unknowingly create that type of distortion on a person, it is like nails on a chalkboard to me. While I realize what is going on, and it makes me cringe, others may not know what it is, but they will just have that gut feeling that it is not a great photograph, without knowing exactly why.

Let’s take a look at an example of that. Last Sunday, when we were leaving church, I asked my oldest to sit down on the stairs. I had my point and shoot camera in my bag, and I took a couple quick shots of him for illustration. While looking at these two shots, let’s run through the process I outlined for Taking a Great Photograph.

Also, these examples are more subtle, because I don’t have much focal length range in my point and shoot camera. But, there is enough to see the effect I am talking about. Most DSLR’s have plenty of range in focal length to exaggerate this effect even more.

The first shot.

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Stepping through the process:

1) Select the focal length that will achieve the desired result.

I failed right away at the first step. I didn’t think about the focal length I wanted to shoot at, and it was wide for the point and shoot camera I was using. I moved in to fill the frame with my subject, and the result is not a great photograph.

I will show a comparison next, but I want you to notice, does something just not “feel” right with this one? I mean, my son is long, tall and skinny. But, the perspective distortion caused by the wide angle focal length makes the subject of the photo look to be his long legs. The face should be the first thing you are drawn to, and it seems WAY back there in the background.

For the comparison shot, I actually made it through a couple steps in the process, so let’s look at that.

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Feel a little more natural? I hope so.

Let’s take a look at the process:

1) Select the focal length that will achieve the desired result.

I knew I didn’t want to be standing on top of him, and since it is a full body shot, I knew I wanted at least a normal focal length. I went just a tad above normal, and shot this with just a touch of compression.

2) Select the aperture that will achieve the desired result.

I knew I didn’t want to have everything in f/16 style depth of field (aperture and depth of field is my next topic). With a small lens, small sensor, I was comfortable setting the aperture at f/3.2 on this shot.

3) Make sure the shutter speed at that aperture is suitable for hand holding your camera.

Yup. Shutter speed was high enough to support hand holding the camera.

Whoo Hoo….I made it through at least 3 items. This is still not a “great” photograph. The lighting is rather flat, the eyes are dark, the composition is not that great (with the pillar in the background not having good placement). Pose is only so-so, and I didn’t work to get any sort of interesting expression. But, the point is that at least I didn’t screw it up because I did not know what effect focal length was having on the photo.

To further illustrate the effect of focal length I want to show the comparison in a little more detail, I took both shots and did a little work on them. I drew a red line from the chin to the top of the head. Basically it is the size of his head in the photograph. I then copied that same line, rotated it and moved it to show its relative size to something in the foreground. In this case, his foot.

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Doing the same process for the second photo, we get this result.

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As you can see, in the second shot, the size of his head is closer to the size of his foot. It is nearly the same length. In the first shot, the size of his head, relative to his foot shrunk about an inch or so. No body parts grew or shrank between taking the photos, so I hope this illustrates how different focal lengths can distort what you are taking a photograph of.

Finally, because of the distance required to fill the frame in “wide angle” focal length, my camera height is at about face level for both shots, but in the first one, I am looking more down on his foot. When I step back for the second shot I am looking at his foot more from the side, instead of looking down on it. Which makes for a more natural look. You can can tell by the angle of his foot in each shot. I promise, he didn’t move!

The second example of perspective distortion is NOT using. Have you ever went on vacation and stopped the car because there is a scenic mountain view? You see tourist all standing around taking photos with their cheap camera and you walk up with your big expensive equipment, snap a shot and guess what? Your photo sucks too! I say that, because I have been there, I know what it is like.

The problem is that you see this grand scene, in 3 dimensions, with a lot of depth, and when you capture it in 2 dimensions, everything looks just flat and lifeless. It is your job to give it back its life and create depth with only 2 dimensions. You want to create a sense of “near” and a sense of “far” in the photograph to give it the depth and life back. Hmm…..near and far….sounds like a good job for the perspective distortion we talked about earlier, and it is!

Without stumbling too much into the realm of composition, this has been a trick of professional photographers in taking landscape photos for ever.

1) Use wide angle to exaggerate distances in the landscape.
2) Place a foreground element “near” in the photograph.
3) Have a background element “far” in photograph.
4) Make space between the two.

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Assuming the light, composition, exposure and everything else is good, you have just knowingly used perspective distortion to create a professional looking photograph.

Telephoto

On the other side of normal is the telephoto range. If a normal focal length makes things look normal, a wide angle exaggerates distances between objects, then it would be a good guess to say that a telephoto shortens distances between objects. And you would be right! It is called “compression” because the telephoto lens compresses the distances between object in a photograph.

Is this desirable? Absolutely. There are some cases where you have no choice, such as shooting wildlife from long distances or sports at long distances. Because the nature of the situation, you are going to get compression from a long lens, and it looks great. But, it can also be a great tool in everyday photography.

If I were to take a bread and butter, business head and shoulders photo, I would want a little bit of compression. We already discussed why we don’t want wide angle. Nobody wants to have a dog nose in a business portrait. Why not normal? If that is the way we normally see things, don’t we want the person to appear as normal? Well yes, the but the problem is that with a normal focal length, in order to fill the frame you end up closer to the subject than you would like to be. Being that close exaggerates things on its own and you will end up still with a little bit of the dog nose effect, which may show itself in the forehead looking too large, or things still being a little bit out of scale.

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So, my head and shoulders photographs are done with a mild amount of compression and a telephoto lens is used. While I said I wanted to keep things simple and stick to 3 ranges, I will say that we are talking about a moderate telephoto lens. You don’t want to use a 300mm lens and stand 75 feet away from subject while yelling posing directions to them 🙂

As a general rule, close up, head and shoulders type shots are done with a mild bit of compression. You can use the same lens for farther back shots, but doing so puts more and more distance between you and your subject. Half body and beyond shots is usually when I switch to the normal focal length.

Let’s do a scenario to see how this would be useful. You are on vacation, or at the park with your kids and they just look so cute that you want to take a photo of them. You want to get a nice, close up shot of them. Instead of just leaving it as a random variable with a random outcome, you say to yourself “Oh….this is going to be close, and this is going to be a tight shot. I want a little bit of compression.” You zoom your lens a touch past normal and then move your body to frame the shot appropriately. You just answered question number 1 on my steps to Taking a Great Photograph, and no longer left this variable to chance.

Finally, you might ask “What focal lengths are wide, normal and telephoto on my camera?” Ugh…..I was hoping you wouldn’t ask that. The answer is, I am going to have to leave that one up to you. There is plenty of information on the web about that, I am trying to create content that I do not think is readily available. The real answer is there are way too many cameras (phone, point and shoot, DSLR) with different variables (DSLR with cropped sensor, DSLR with full frame sensor), etc for me to give an easy answer. I generally shoot a medium format camera which can make things even more confusing!!!

So my advice on this one is google it! If you still struggle with figuring this out, feel free to drop me a line and I will try and help you out.

Finally, remember that what I said about focal lengths are just guidelines. There are always times when “the rules can be broken.” But, in knowing what you are doing with focal length, you are choosing to break the rules, and you know why and what is going to happen, rather than leaving it to chance.

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In summary:
1) Select the proper focal length for the “effect” you want the photograph to have.
2) Move your body to appropriately size and place your subject(s).
3) Follow the rest of the items on my Taking a Great Photograph Checklist, which we have not covered yet!

If some of those steps did not make sense, don’t worry. We haven’t covered all those topics yet. Do as many as you understand and we will keep going. That process won’t change through this whole series. We will just learn more about each item.

Happy shooting!

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