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What Is Pinhole Photography? Camera Basics Explained!

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A country farm landscape using pinhole photography

They say photography is an art. And just like any other art, it exists in several different forms. You could be a specialist in architectural photography if you wanted to, or a sports photojournalist who’s all about chasing that adrenaline rush.

You could also have a passion for still-life photography, or be into fashion and explore fashion photography. The point is, this art is the kind that caters to the needs of any creative, as long as they are willing to listen and learn.

In today’s art session, we’ll be learning about the principles of pinhole photography. So, if this is something that you think would interest you, keep on reading. A pinhole camera is a small, simple camera without a lens that produces an inverted image.

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How Does It Work?

One of the main properties of light is the fact that it always travels in a straight line. Let’s say you have something hollow like a pipe, and you’re trying to look for a light source. You’ll easily and quickly pinpoint the direction of the source because all you have to do is follow the light being emitted.

However, if for some reason you decide to bend that same pipe, all you’ll see is darkness. And the reason is simple—light cannot travel on a path that’s bent. This property of light has a name, called the “Rectilinear Propagation of Light.”

The other aspect that’s worth mentioning is the electromagnetic nature of light. That basically means that parts of light are made up of magnetic and electric fields. Fields that, by the way, are perpendicular to each other. Seeing as light is a wave, it’s able to produce its own power, ultimately influencing its observable color and wavelength.

Testing The Rectilinear Propagation Property of Light

Low angle pinhole photography on railroad tracks
Image Credit: Kush Kaushik, Pexels

To explain this, we’ll have to conduct a small experiment. “Small,” meaning this is not the type of experiment that demands a long list of materials or one that is time-consuming. Go get a light source (you’re allowed to use a light bulb, flashlight, or candle), a paper cutter or pair of scissors, and two cardboard planks.

Next, make circular holes in both planks, and ensure that they are completely aligned with each other. Remember, this is the most important part of the experiment, seeing as we’re trying to prove that light doesn’t travel in a curvy trajectory. Use a thread if you have to, to ascertain that those two holes are aligned.

Once you’re done, hold up the planks close to each other (make sure they are parallel to each other), and try to look for the light source from one end. At this point, if you followed our instructions to a tee, you won’t experience any problem spotting your candle or bulb.

Now let’s try something different. Place one of the planks next to the light source and hold up the other. But this time around, we want you to make sure that the circular holes that you made on the cardboards are NOT aligned.

Is your light source visible? Obviously not. And do you know why?

Well, it’s because the holes and light source are no longer aligned. The light emanating from the source did travel the way it’s supposed to but couldn’t reach you due to some impediment. It was blocked by parts of the displaced board the minute you shifted the hole.

But you can remedy this by placing the hole in the original position. Thus, proving the rectilinear propagation of light is actually a property worth taking into consideration, anytime we’re using optical pieces of equipment. Like, for example, the pinhole camera.

This camera is not as sophisticated as the DSLR or mirrorless cameras that have dominated the various fields of photography. It doesn’t come with a lens or any other component that’s typical of a fancy camera because all it needs is a pinhole.

In physics, we’re often reminded that light travels from an object to our eyes, and not the other way round. So, when the light from your subject finds its way past the pinhole, the kind of image that will be produced at the other end of the camera will be inverted. A phenomenon that’s known as the “camera obscura” effect.

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Where Is It Used?

Windmills in the horizon using pinhole photography
Image Credit: Rawpixel

Generating Eccentric Images

Like every other camera, the work of the pinhole camera is to generate images. However, besides the obvious, this genre of photography offers something special. You see, the images being created in this case are very unique, in the sense that they exude a continuous depth of sharpness at varying distances.

On top of that, pinhole photography is the only genre that allows photographers to capture a wider range of electromagnetic frequencies found in the spectrum—frequencies that significantly contribute to the unique nature of the images.

Image accuracy is the other reason why we find ourselves turning to pinhole photography. Unlike traditional cameras, the pinhole camera isn’t affected by the reflective properties of light, which normally plague lenses. So, chances are, if the conditions are right, the photographer will be able to produce an image that’s an exact replica of the subject.   

Experimental Photography

This right here is sort of like a double-edged sword, because depending on the type of photography you’re going for, it could work in your favor or against you. Not having a lens means your pinhole camera will need more time to capture the image of a subject. It could have worked a little bit quicker if it had a lens to focus or amplify the image onto a film.

To produce a sharper image, being the photographer, you’ll have to ensure the device remains still, open, and pointed at the subject, for a considerable amount of time. Investing in a tripod is a good idea.

Experimental photographers usually see these long exposure times as an opportunity to try out unconventional techniques of photography. You’ll find them toying around with the camera, trying to capture partial images of their subjects. The blurry sequences normally make it seem like the objects were moving while being recorded.

Editing Negatives

Conventional cameras are designed to only use specific types of films. You cannot use a film meant for a DSLR camera on a mirrorless camera and vice versa. But when it comes to the pinhole camera, you can work with pretty much any type of film—not even the size will be an issue.

This flexibility is what makes it possible for pinhole photographers to create different types of negatives. So, if you dislike editing small negatives due to the hassle involved, you could opt for larger ones.

Man in grayscale city backdrop
Image Credit: _Paweł L., Pexels

Surveillance

The materials used in the construction of a pinhole camera can’t be detected by a magnetic device or one that relies on electricity. And this makes it ideal for investigators looking to set up a sting operation.

You could even go as far as taking 360-degree images of the subject, by creating holes on all the sides of the camera’s housing. Just don’t forget to mount the film at the center using a cylindrical roll, or you’ll only be able to capture parts of the subject.

Solargraphy

Solargraphy is the art of creating solargraphs. These are essentially recordings of the sun’s path, as it crosses the sky. It’s also referred to as uncountable photography because you get to capture several images of the sun using a pinhole camera, over an extended duration. It’s a really long and tedious process, seeing as the exposure periods are usually measured in months.

Advantages Of Pinhole Photography
  • Ideal for beginners
  • Capturing the images is an enjoyable process
  • The images look eccentric/unique
  • It’s cost-effective
  • Offers an extensive depth of field
  • Utilizes any type of film
  • Doesn’t get affected by electric or magnetic fields
Disadvantages Of Pinhole Photography
  • Prolonged time exposure can be a turnoff
  • Simplicity is not everybody’s cup of tea
  • Doesn’t quite focus on the nitty-gritty details of the subject

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Frequently Asked Questions (FAQs)

Early pinhole camera
Image Credit: Rawpixel

Who Invented the Pinhole Camera?

Even though some sources say that the pinhole camera was first invented in the 5th century BC by Mozi—who was a Mohist Philosopher at the time—an Arabian physicist, astronomer, and mathematician who went by the name Ibn Al-Haytham, has been credited as the first person to invent the dark chamber, also known as the camera obscura. 

Ibn Al-Haytham lived during the Islamic Golden Age and made several other contributions to science that earned him the title “The Father of Modern Optics.” He’s the guy who also demonstrated how we could use light to project an object’s image onto a flat surface.

Where Was Pinhole Photography First Applied?

The first person to show us the benefits of a pinhole camera on a larger scale was an astronomer called Gemma Frisus’ De Radio. And he did that by using his camera to observe the solar eclipse in a darkened room. This was way back in 1544, and the reason why we now use pinhole cameras in solargraphy.

What Causes the Image Inversion in Pinhole Photography?

So, we’ve already established that light always travels on a straight path. When you place an object in front of the camera, the ray that’s traveling from its top part will pass through the hole, before hitting the bottom part of the screen at the back.

At the same time, the ray that’s traveling from the bottom part of the said object will also pass through the hole but hit the top part of the screen. Hence, creating an image of the object, but inverted.

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Final Thoughts

Before we sign off, we’d like to recap what we just learned. Firstly, a pinhole camera is a simple optical concept that doesn’t utilize any type of lens. It subscribes to the basic principle of light, which is light travels in a straight path. Secondly, the image created by a pinhole camera is always inverted, because the light rays that travel from the object’s top and bottom parts crisscross at the hole, as they pass through it. And lastly, it often provides an extensive depth of field.


Featured Image Credit: Phil Dolby, Pxhere

About the Author Robert Sparks

Robert’s obsession with all things optical started early in life, when his optician father would bring home prototypes for Robert to play with. Nowadays, Robert is dedicated to helping others find the right optics for their needs. His hobbies include astronomy, astrophysics, and model building. Originally from Newark, NJ, he resides in Santa Fe, New Mexico, where the nighttime skies are filled with glittering stars.