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Optical Zoom or Digital Zoom – Zooming Your Way to Home Security

Digital-ZoomSo you’re in a hardware shop, looking for a security camera. (Tip: They are in Aisle 14) Browsing through their products, you've noticed 2 cameras that fit your budget perfectly but you don’t know which of them to buy. One of them says it has 12x optical zoom, the other has 18x digital zoom. Which of them will you choose?

Some will take the numbers (12x and 18x) as their determining factor. Some will ask, what’s the difference in optical zoom and digital zoom, and then decide depending upon the answer. And I believe there’s a few who won’t care as long as there’s a “zoom” in it. This article answers the question of those who are asking about the difference between optical and digital zoom because there is a difference.

What is Optical Zoom vs Digital in Home Security

First, what is an optical zoom and what is a digital zoom? Simply put, an optical zoom manipulates the hardware to zoom into an object while digital zoom uses software. To zoom in on an object, a camera with an optical zoom adjusts its lenses so that the lenses move closer to the object.

Imagine that you are in an art gallery, staring at a beautiful painting. You noticed that you cannot clearly see some small details in the painting because you are a few feet away from the it. So you move your head closer to the painting. That is how an optical zoom works. On a photography camera, the lens will actually expand sometimes significantly. But don't worry! The lenses on home security cameras do not project by feet or even inches. In fact, they are powerful enough that adjusting it by a few millimeters will make a difference in your output.

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Now a digital zoom is different and by far the most common technology found in home security cameras. Digital Zoom is used on Dropcam, FLIR, and many more. Digital Zoom takes a look at the entire field of view and then let's you crop out what you don't want to see leaving the part that you want to see. It works best when paired with a camera that has a wide-angle lens that covers a large visual area. Digital zoom technically crops that large visual area so that you can "zoom in" on the area you want to see. Some cameras will add a second layer of software that is used to fine tune the details on the crop making the digital zoom more effective.

So let’s go back to the gallery. Now this time, you are not allowed to move closer to the painting, so you take a picture of the whole painting instead. As you get home, you connect you’re camera to your computer, and then enlarge the photo and focus it on the part that you want to look more closely at. That’s a digital zoom.

Digital vs Optical Zoom

Is there a difference? There is. The greater you zoom in on a camera that uses digital zoom, the lesser the quality of the picture is because it does not really zoom in on an object but instead it just enlarges the picture. Optical zoom produces a clearer zoomed image. So if you compare a 12x optical zoom and 12x digital zoom, the output of the optical zoom is far better.

But what if the digital zoom has higher zoom capacity than the optical zoom? This is what happens: After zooming in using the 18x digital zoom, what’s left is something that looks like a bad case of psoriasis—pixilated, blurry, and smoky. On the other hand, use the optical zoom and you will be able to get a clearer picture.

Most of the time, optical zooms are preferred in cameras because of the quality. But digital zoom also has its advantages. First, digital zoom does not reduce the angle of view, optical zoom does. So if the view is already zoomed in using an optical zoom, someone from the side can throw a rock on the camera without being caught on tape. Second, digital zoom can be added after the recording has been saved, so you can get the whole picture and only if the need arises do you need to zoom in. These are reasons why digital zoom is more common in security cameras.

Featured Photo: "Are You Ready" by Shazeen Samad. Used under a CC BY 2.0 license.