CameoAppearance and the Blog of Many Things

A close perspective exaggerates distance and shapes. Near things look bigger, far things look smaller. But if you take a far perspective and magnify to equal size in frame, distances and geometry remain more stable and less distorted.

If you've ever taken any art classes, you may have learned about the vanishing point where all angles converge off into the distance.

Buildings are not the only thing that has a vanishing point. They just have simple geometry, which helps you observe the effect.

This close perspective of a dog is no different from the buildings.

Something without perspective is called an orthographic projection. This is where all angles are parallel forever—with no vanishing point.

As you move farther away, a perspective projection appears to be almost orthographic. And if you magnify that far perspective, it looks similar to an orthographic cube.

But the far perspective still has a vanishing point, it just takes much longer to converge.

This video game allows you to play with perspective or orthographic projections.

The near cubes look very different. But the far cubes have similar geometry.

Why does a close perspective look distorted? Why does a far perspective look nearly orthographic?

This all has to do with the relative distances from the point of view of the observer. Let's move on to the real world to help explain this.

Perspective distortion is caused when the lens is very close to a subject. Only wide angle lenses have the field of view and the close focusing distance to get close enough to create severe perspective distortion.

Despite erroneous claims of eyeballs being like 50mm lenses, humans actually have a decently wide field of view. If you hold the end of a long cylinder close to your eye, you will see the same geometric distortion and dramatic vanishing point. When people are accused of misjudging the size of... cylinders, it's possible they just had a very close perspective that exaggerated geometry.

Perspective can alter our perception of size.

So the lens gives you the ability to *see* the distortion, but it doesn't *cause* the distortion.

Image 1 is taken a few inches from the subject with an ultra wide angle lens. It is magnified by moving closer.

Image 4 is taken from much farther away. It is magnified by using a telephoto lens.

Why does his left ear disappear in image 1?

It's a simple case of obstruction. The cheek is literally in the way at that near perspective.

If I stand very close to this wall, I cannot see the walkway to the right.

The walkway is physically obstructed at this close perspective. I can't see around corners.

But if I change my perspective…

Light needs a clear pathway to the point of observation.

Why does his ear seem to grow larger and larger as the perspective changes?

If you'll excuse my bad drawring...

In the top example, the lens is only 2 units away from the nose, but it is 6 units away from the ear.

The ear is 200% farther away than the nose.

In the bottom example, the lens is now 30 units away from the nose and 34 units away from the ear.

The ear is now only 14% farther away than the nose. The relative distance is less exaggerated.

Distant ear percentages are hard to visualize. What if I moved only my nose 200% closer?

If we upscale this concept, it can be easier to understand.

(My examples are going to be shitty smartphone photos taken at night with my trash bins. I'm hoping you will forgive that. If I had more energy, I would have taken better photos with more appealing subjects.)

These two trash bins are only a few feet apart. The black trash bin represents the ear. The blue trash bin represents the nose.

If I take a photo from a foot away...

From this perspective, the black bin is roughly 80% smaller than the blue bin. The blue bin is very close to the lens. The far bin is several hundred percent farther away from the lens. So it takes up a very small percentage of the frame.

So, big nose, tiny ears.

What if we magnified this perspective?

Note the little box on the house far in the background.

If we crop the image and thus magnify the same perspective...

That little box looks much bigger. But this "telephoto" field of view does not allow us to see both trash bins. The perspective hasn't changed, just the magnification.

I am making something small in the background much bigger. The distant perspective makes the object more orthographic. And when I magnify that perspective, it appears more compressed, more flat.

This is a digital crop of a wide field of view. A telephoto lens is essentially an optical crop. It magnifies the perspective in the same way. The advantage of an optical crop is that it maintains all the detail. Whereas a digital crop throws away a bunch of pixels.

A magnification of perspective is often referred to as "lens compression." This is an inaccurate legacy term that causes much confusion. It would be more accurate to call it "perspective compression," but it is very hard to change terminology in photography education.

The lens is not compressing the object. I used a very wide lens and just by cropping after the fact, I was able to get the same perspective compression as if I had used a telephoto lens. The wide field of view makes far away stuff very tiny in frame. So we struggle to notice the flatness. It isn't until we magnify the distant object that the "compression" becomes more apparent.

What if I wanted to make the nose and the ears about the same size?

I'd need to change my perspective.

Now both trash cans take up roughly the same amount of space in the frame. They are still the same distance from each other. But from this perspective, they are both about the same distance away from the lens.

And now, let's magnify this perspective.

When you magnify a perspective, you magnify everything in the photo. The house behind is bigger. The light in the far background is bigger. Everything looks more orthographic. More two dimensional. And so it has that "compressed" perspective.

And because the perspective is from farther away, the percentage distance from the lens is much smaller. The black trash bin went from being 200% farther from the lens to 10% farther from the lens. The distance and geometry become less exaggerated.

Now let's line up all of the trash bins from both near and far perspectives and magnify them the same amount.

Look at that cute little guy.

How can we use this knowledge in a practical way?

By changing your mental model to perspective rather than the focal length of the lens, you can take control of how much perspective distortion you allow in your photos.

Let's use the humble selfie as our example.

Smartphones typically have a main camera with a wider field of view. And when you fill the frame with a face, you may get some unflattering perspective distortion.

I know that this distortion is not caused by the lens. It is caused by the camera being really close to my face.

So if I hold the camera farther away and change nothing else...

My face looks less distorted. However, it is taking up a much smaller area of the frame. But since modern smartphones have pretty good detail, I can just crop. I can magnify this farther perspective.

And when you compare the exact same framing from the near and far perspective...

The only variable I changed was extending my arm. It's the same wide angle lens.

You'll notice that the farther perspective made my head look bigger. I have a big head, that's fine. But this demonstrates another common photography fallacy. It is often said that 85mm lenses are the best for headshots and portraits. The idea is that compressing facial features is more flattering. But if someone has a big noggin, a telephoto lens may actually exaggerate their cranial prowess.

For people with larger or rounder heads, you may need to test different perspectives—different distances—to find a balance between compressing facial features and not exaggerating their head. 50mm might be more flattering for them.

I think photos of myself with a magnified distant perspective overwhelm people with the size of my dome and the luxuriousness of my mane.

At 85mm, the camera has to be farther away and it gives that imposing orthographic effect.

But at 50mm, I think my head feels a bit less... Megamind.

If you have a small or slender face, you may look best at 100mm or 200mm—because longer lenses force the camera to be farther away.

You can test what perspective works best for your head shape and facial features. But try not to think of it in millimeters. Think about how far away the camera is. This works even with a smartphone. You just place the camera at different distances, crop all the photos so your head has the same framing, and figure out which distance flatters you the most.

And then if a photographer is taking your picture and they seem too close or too far away, you can nudge them to the appropriate distance. And that distance will dictate what lens they need.

What I call "common perspective" is based on the distance we are most comfortable when interacting with other humans.

When people say a 50mm lens is closest to the human eye, they are actually talking about this socially accepted distance. Our eyes have a wider field of view—so it isn't that our eyes match a 50mm, but rather the perspective the lens must use to fill the frame with a person's face matches our common comfortable perspective.

For headshots, photographers will typically move a little farther back than the common perspective and then use a slightly telephoto lens to magnify it. This still gives an intimate feel while flattening facial features and flattering proportions.

As I mentioned, it is important to consider head size and shape when using this farther portrait perspective. For big heads it can help to move closer and zoom out a bit. For slender faces you may want to move farther back and zoom in.

A far perspective with a wide field of view gives a sense of the environment. The space the subject occupies becomes a secondary character in the composition.

A distant perspective that is magnified can create an "observer" effect. As if the subject is being viewed from afar. This is great when you want to give the composition a feeling of isolation.

This is also why super telephoto paparazzi pictures can sometimes feel extra unsettling or invasive.

You can use perspective distortion to play with exaggerated size and geometry. A close perspective with a wide field of view can create some really fun and creative compositions.

And another cool perspective effect is to shoot from a low angle. This is often how "power poses" are photographed. You angle the camera slightly upward from below the subject's eyeline and it gives a sense that they are towering over you.

This can be subtle...

Or exaggerated...

In summary...