How Does a Digital Camera Work: A Quick Guide

By Arindam Roy

If you just bought a camera, chances are you’re probably dying to figure out how it works. There’s nothing more discouraging than an expensive purchase that just sits around collecting dust because you don’t know how it operates.


The reality is, though, that if you were to read the instruction manual from cover to cover, you’d probably learn very little — it’s simply not written in a manner that is meant for you to understand. And if you don’t fully understand how your camera works, how could you possibly be expected to take great photos?


This article will shed some light on the basics of how cameras work. It is far from comprehensive — that would require an entire textbook on digital photography — but it should give you a good foundation for getting started. With that said, let’s begin!


How digital cameras work


Cameras have been around for a long time now. They have evolved significantly over the past several decades, but they basically work in the same way today as they did when Kodak introduced its box camera in 1888.


A typical digital camera consists of the following components:


Image Sensor:

The heart and soul of any digital camera is its image sensor. A sensor converts light into an electrical charge — this is how all photographs are captured (on film or digitally). The sensor in a digital camera is designed to be more sensitive to light than a film emulsion so that it can register an image with greater detail. The size of a digital sensor varies depending on the manufacturer and target market for the camera, but it’s usually no larger than about 20mm x 15mm. Sensor chips are placed on a tiny circuit board called an so-called image chip (if you’ve ever seen a digital camera’s viewfinder, you’ll have noticed that there are more than one sensor on the chip). The sensor is read by a light-sensitive electronic device known as a pixel engine. (There are usually up to 16 pixels on one “pixel”.) The pixel engine is programmed with the data from the image sensor to be able to capture an entire picture at once.


How Does a Digital Camera Work

Also read: What are the Health Effects of Tin Foil in a DSLR Camera


The viewfinder is simply a window that lets you know what an image looks like as it’s being captured. One might think that it’s not necessary to have a viewfinder on a digital camera since there is no film that needs to be advanced after each picture is taken. However, the viewfinder is still an extremely important component of any digital camera. Why? Because it allows you a chance to compose your photograph before taking the actual shot. A good LCD screen can help you with composing photographs as well, but nothing beats being able to see exactly what you’re shooting right through the lens of your camera.


The shutter opens when light hits the image sensor and closes when there’s no more light reaching the sensor. Each good photo requires a number of photos to be taken, and the shutter is the only component of a digital camera that’s constantly moving throughout the process. To maximize your chances of taking a great photo (and to minimize your chance of having it ruined when you take too many photos), make sure to use a slow shutter speed.

Read more: Things to Know When You Use a DSLR Camera


The lens allows light to enter the camera and focus on the sensor. The size, focal length, maximum aperture, and number of glass elements in a lens have no bearing on how well your photographs turn out — all you need are clear glass surfaces (with no imperfections or scratches) that are working together with the sensor chip on the image chip. (The more optical elements a camera has, the brighter and clearer the images will be. However, this also decreases the amount of light that can enter a camera.)

How Does a Digital Camera Work

Memory card:

The memory card stores all the data from your digital photos. It’s important to note that images are digitized data — they are never stored in an analog format such as JPEG or TIFF, and they are not stored as pixels. They are simply zeroes and ones (binary code). A memory card can be removed and replaced with another at any time — it is not necessary to erase all the images on a memory card before inserting a new one.

Related article: How to Set up a DSLR Camera


Q: Which camera should I buy first?

A: It is very important that you make the right decision when choosing your first dslr camera. The wrong choice can result in buying a camera with poor quality, and will limit your ability to take great photos. You can use a variety of resources to help you make the right decision, but it is always best to ask for advice from someone who has actually purchased a camera before.

Q: Can I buy the base model of an SLR Camera?

A: DSLR cameras do not have interchangeable lenses like point and shoot cameras. The camera needs to be purchased with the interchangeable lenses it comes with when you purchase it.

Q: What is the most important thing to look for when buying an SLR camera?

A: The most important thing to look for when buying an SLR camera is the capability of taking a high quality image. There are two main factors that contribute to this. The first factor is the size of the sensor in your camera. The larger the sensor, the more light that will be captured and translated into a better image with less noise present. A sensor may be different sizes depending on what brand of camera you purchase, so it is important to compare different brands with similar sized sensors before making your final decision. You can find out what size sensor different cameras have on their specifications page or manual. The second factor is the quality of the lenses of the camera. The lens that comes with an SLR camera is generally a very low quality lens, and it will make your camera produce a much lower quality image as well. You should always purchase at least one high quality lens along with your dslr camera.

Q: Can I get a free SLR Camera?

A: While you can’t get an SLR camera for free, you can get some sweet deals on them if you have patience. They are available online and in stores. If you are looking for a deal, keep your eye out during holidays, such as Black Friday or Cyber Monday or around big events like the Olympics. You may even find a great deal if you plan ahead.

Q: Should I get an SLR camera for underwater photography?

A: If you are just starting out in underwater photography, then yes. It is less expensive to get an SLR camera than to rent a waterproof camera. You can find deals on these cameras on sites like or Ebay. They are available at discounted prices at times as well.


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