Numbers Can Be Deceiving – Digital Zoom vs Optical Zoom
You see it all the time in digital cameras: digital zoom and optical zoom. The camera companies want you to see the digital zoom number, which is usually higher, and think you are getting a great zoom on your camera and a great deal, but you really aren’t.
Here’s an example of the digital zoom number being deceptive. This is a true story that happened a few years ago. A friend of a friend bought a camera from a coupon ad. He thought he was getting a great deal. It was something like 20x zoom (which was digital) for fifty dollars. Instead of a great camera, he got a piece of garbage. Not only was the zoom bad, but the camera wasn’t even a 1 megapixel camera. I think it was VGA quality.
So, what do you want to look for when you are looking at the zoom features of a digital camera? You want to look at the optical zoom, not digital.
Avoid Digital Zoom
Here’s how I explain the difference to my students. Digital zoom is a zoom done by the computer in the camera. It is like the zoom tool you use in Photoshop or other photo editing programs. The more digital zoom your use the more pixelated your image is going to get, just like the more you zoom in on an image in a program the more pixelated it gets. It might not be noticeable with a little zoom in effect, but zoom in all of the way and you will notice it. You will also notice more of a blur on cameras with lower megapixels when digital zoom is used. I have never had a good picture with digital zoom in use. In fact, I turn it off in every camera I get so that I don’t accidentally use it.
Optical Zoom is The Zoom of Choice
The zoom you want to pay attention to on a digital camera is optical zoom. Most pocket sized cameras will have at least 3x optical, although that number is getting bigger. As cameras get bigger in size they tend to be able to have a larger optical zoom. Larger optical zoom cameras also tend to have a feature called image stabilization to help you steady the image when zooming in from such a long distance away.
What is optical zoom? Optical zoom is what I call a real zoom. It is the zoom performed by the lens of the camera. It is the zoom all film cameras used before digital took over. Since optical zooms are done with the lens and not the computer, you are getting a crisp image or zoom every time (unless of course you take a bad picture).
One tip I always tell my students when dealing with zoom is let the camera optical zoom you in as far as possible. If you still want to get closer crop the image on the computer. You’ll have a better chance of getting a crisp image that way instead of getting a blurred image from digital zooms. Plus, at least you will have a good picture, even if it is not zoomed in as far as you would like.
So next time you go shopping for a digital camera remember to ask about the optical zoom and don’t pay any attention to the bigger digital zoom number.