How Cameras Work {Beginner Photography Class}

Why do I Need to Know How Cameras Work?

I can already see you scowling at the screen. “Seriously? I was hoping you were going to show me how to make beautiful pictures! I don’t care how cameras work !” Don’t click away yet!

Knowing how cameras work will help you understand how to make better images.  When you understand what your gear is doing, you know how to use it to create the image you want.

Don’t worry, I’m not going to bore you with unnecessary details about megapixels or 35mm film or image resolution (these are things I still barely understand!).  So lets dive in together, shall we?

What is THAT?!

How Cameras Work.

This is a pinhole camera.  If you distill a camera down to it’s simplest form, you’ll get what you see above. You can make a camera out of a box, or a can, or an oatmeal container. It just needs to be light-tight except for that tiny pinhole and have some light sensitive material to record the image.

How Cameras Work

We’re going to grossly oversimplify this so I don’t lose you.  Below is a diagram of a camera and a quick bullet list defining all the parts.

How Cameras Work: Diagram of a Camera

    • Light: I know, technically not part of the camera; however, it’s essential to the process so humor me! When you make an image, you are recording the reflection of light. Colors reflect light differently.  Black gobbles up light completely, white reflects it all back, and the rest of the colors do something in between.  Your camera’s job is to capture reflected light.
    • Enclosure: Your camera’s body.  The cardboard box in the pinhole camera above. Your camera enclosure is probably a nice little plastic or metal thingy with a variety of buttons, screens, and a viewfinder.  The main purpose of the enclosure, outside of giving you something to hold, is to keep all light out! Any light leaking through the enclosure will make capturing an accurate image nearly impossible.
    • Lens: The thing that focuses the light on your recording medium. Our pinhole camera doesn’t technically have a lens. But your camera probably does.  Whether it’s detachable or not depends on the type of camera.
      Lens come in a variety of focal lengths; they can be  wide (so you can see the whole mountain range) or telephoto (so you can stand on the sidelines and capture the game).  They can be fixed/prime (only do one thing: wide, or telephoto) or zoom (switch between the two). Camera users can switch lenses or use different focal lengths for different effects.
    • Aperture: The hole that lets in the light. The pinhole camera’s pin hole (literally… pin sized) lets in very little light but creates an image where everything is equally in focus across fore, mid, and back grounds. Our cameras have much larger aperture holes and therefore do not focus equally in all parts of the image. This is going to be a key concept later! Aperture is generally in a part of your lens referred to as the aperture ring.
    • Shutter: The Shutter is the screen covering your recording medium until you are ready to take your image. See that piece of square tape in the middle of the pinhole camera, that’s the shutter. Your camera shutter is internal. That button you press is called the Shutter Release and it causes the shutter to move out of the way. Camera users can change how quickly the shutter.
    • Recording Medium: This is what records your image so you can view it later.  With the pinhole camera, it’s most likely a piece of film.  With digital cameras, it’s a light sensitive sensor. The size of your recording medium (both film and sensors) directly effects the detail quality of your image. The larger your recording medium, the more detail you’ll see in your final print.
      Additionally, recording mediums are like skin: some sunburn in 30 minutes and others take 5 hours to even tan up a bit. You don’t want to use a recording medium that sunburns easily on a bright day nor do you want to use one that takes hours to tan up when you’re working with less light. This speed of recording light is called ISO.

Why all This Matters?

There’s two things you can’t change when you press your shutter release button: the enclosure of your camera and the light reflected from your scene (although you can modify/control the light with flash or location change). But there are 4 things that you can change, usually with a click of a few dials or a quick lens change.

When you know how cameras work, you can begin to understand how and why to change lens, aperture, shutter speed, and recording medium (ISO) to get the results you want. 

Mini Homework

This is probably the simplest and most annoying homework you’re going to get. You’re really going to hate me for this and I’m likely going to repeat this mini homework a few times.

READ YOUR CAMERA’S MANUAL! Maybe not the whole thing… because that’s probably more than you want to bite off at one time.  We’ll be doing a lot of camera manual browsing throughout this course and each time it will be more in-depth and specific.

This time through your manual, I want to you find sections that tell you how to zoom or change your lens (if applicable), change your aperture, change your shutter speed, and change your ISO.  But don’t just read.  Depending on your learning style you might want to highlight these sections with different colored markers. You might want to YouTube your camera model and see if you can watch someone else change these things up.  You might want to pull out your camera and practice toggling those buttons.  You might want to dive in and just play with those settings and see what happens.  Do whatever it takes for you to get a feel for the vocabulary introduced above.

If you have any questions please, jot them down in the comment section below. No question is stupid.  We’re all here to learn.  I’ll do my best to answer each of them.  However, this week might have a lot of  “We’ll get to that in a different lesson.”  type replies.  When I post on that topic, I’ll try to come back and link you to that post.