These days, almost every camera with a built-in lens has some sort of a “zoom” label on it. However, not all types of zoom are created equal, especially if you include cell phone cameras. There are two major different technologies that are used: digital zoom, and optical zoom.
What’s The Difference Between Digital And Optical Zoom?
Digital zoom and optical zoom are two very different things, indeed. You might even say that one is “fake”, and the other is “real”! However, it’s a little more complicated than that, so we’ll explain it very simply right here:
Digital zoom refers to an all-electronic form of zooming in or out. Meaning, nothing on your camera is actually moving! The only zooming that is happening is in the camera’s software and processing: the image is being cropped to zoom in, or un-cropped to zoom out.
You might call this “fake” zoom, if you’re a purist, but the technology is getting very good these days, so let’s come back to this in a minute…
Optical zoom refers to when the camera lens’ glass elements actually move back and forth, to truly zoom in and out. This usually means you get much better image quality, as long as the lens itself is sharp.
Traditionally, serious photographers consider this to be the best way to zoom, however, moving parts will always make a lens bigger, more complex, and in some cases, just not very sharp. Therefore, many photographers these days will make a decision to use either digital or optical zoom, or a little bit of both, depending on the situation.
What does “Zoom” Mean? What Does “3X” Magnification Mean?
Digital or optical, what IS zoom, actually? Technically speaking, a zoom lens is a single lens that is capable of zooming in and out. It’s that simple! The term zoom alone does not mean a lens has a specific focal length or magnification.
However, a lot of zoom lenses do use magnification to measure how much zooming effect they have. So, unfortunately, there is a common misconception about the term, because they use numbers like “3X Zoom” which makes it sound like a reference to actual magnification, but it’s not.
The magnification of a zoom lens is measured in relation to its widest angle of view, but, that isn’t always the same. For example, some zoom lenses’ widest angle of view is equivalent to 28mm, and other zoom lenses’ widest angle of view is equivalent to 24mm, which is a little bit wider.
A “3X zoom” doesn’t mean the subject is actually magnified 3X. It just means the lens can zoom to three times that widest focal length number. So, a 3x zoom that starts at 28mm would zoom in to 84mm, but a 3X zoom that starts at 24mm would only zoom in to 72mm.
Of course, there are all types of zooms, in fact, other lenses are 5X, or even 10X, such as the Canon RF 24-240mm f/4-6.3 IS.
[Related Reading: Macro Photography Explained, Magnification, Reproduction, & Focal Length]
Which zoom lens focal range or magnification is right for you? That depends on what type of photography you do, and your creative style, some photographers prefer a zoom lens that is more wide-angle, while others prefer a lens that is more telephoto.
With optical zoom, a camera can give great image quality at any focal length, wide or telephoto.
With digital zoom, a camera will give its best image quality at its widest focal length, and “zooming in” will actually be equivalent to just cropping in from that widest angle.
Digital Zoom Technology Is Improving
The good news is, many cameras with digital zoom these days are actually getting better and better. With very high-tech sharpening algorithms, using digital zoom can be more than enough for capturing images that are only going to be shared on Instagram, Facebook, or videos that are going to Youtube or other social media pages.
Some cameras, especially cell phones, with digital zoom have extremely high-megapixel sensors, too, capable of 8K video and stills, which means that you can still record 4K or 1080p video with barely any loss of quality, or make very large prints of your still images and still have them look great!
The Difference Between Zoom and Wide Versus Telephoto Lenses
Before we wrap up, let’s clear up one more thing. A lot of people confuse “zoom” with a specific type of lens. (Usually, telephoto lenses) It’s even worse these days with cell phone cameras, because manufacturers are actually calling some of their lenses, for example, “5X” (zoom), when in fact, they are just a telephoto lens, NOT a zoom lens.
Just remember that a zoom lens is one that actually allows you to not just take pictures at one wide-angle focal length and one telephoto focal length, but any angle of view in between, too.
In fact, “zoom” does not just mean a telephoto lens, either. There are wide-angle zoom lenses, normal zoom lenses, and telephoto zoom lenses. What makes them zoom lenses is nothing other than the fact that they can actually zoom in and out.
This is usually the case with digital zoom on cell phones, however, some optical zoom lenses on cell phones these days are actually just three or four different prime lenses, and you are only able to shoot at those prime focal lengths if you want the maximum optical quality; shooting in between those optical focal lengths is either your only option, or it requires using digital zoom.
Of course, having two, three, or four optical lenses on a cell phone camera is usually still a very good thing, in fact, many of the best cell phone cameras are beginning to rival the final image quality of much bigger professional cameras!
Either way, now you know everything there is to know about optical zoom and digital zoom! Be sure to use this information when considering your next cell phone camera or any point-and-shoot digital camera.
Follow his wilderness nightscape adventures on Instagram: instagram.com/astrolandscapes