Optical Zoom vs Digital Zoom – What’s the difference?
This week on the blog I did a review of the Nikon P100. I was inspired to do so because of a video my dad , Joe made about it at Diamond Imaging. You can check out the video here and see him do a hands on review of some of the best features of this camera.
One of the most powerful features that struck me is the size of it’s Optical zoom lens. You can see the pictures we took with the camera, standing from the same spot and you’ll notice how much you can see with that optical zoom lens without loosing any quality – it’s pretty cool!
Nearly every digital camera has some form of an optical zoom lens these days and it’s almost something that we have come to expect. It’s rare to see a compact camera with a fixed focus lens – usually this is left up to the camera phones although these are even beginning to have zoom lenses too.
Most camera have both an Optical Zoom lens and a Digital Zoom lens – so what’s the difference?
Optical Zoom Vs Digital Zoom
An Optical Zoom lens will allow you to take subjects that are much further away without loosing any quality. The camera uses the true optical capacity of the cameras lenses to magnify you subject hence rendering a clear crisp image. You’ll see the size of the optical zoom of your compact camera denoted somewhere on your camera body or perhaps on the side of the lens e.g. 3X Zoom, 5X zoom, or in the P100’s case 26X Zoom.
A Digital Zoom is quite different Instead of using the optics in the camera lens to bring you closer to your subject, the digital zoom simply digitally magnifies the image that you already can see through your viewfinder. This has the same effect as what happens if you zoom in on a picture on you computer, in effect magnifying the pixels. You loose resolution or picture quality. Lot’s of compact cameras will boast a large digital zoom but in reality this means little to what your camera can do.
Most compacts have a combination of an optical and digital zoom. When buying a new compact camera always be clear if the zoom size advertised on the box is the true optical zoom or if iti is in fact the combined size of the digital and optical zoom. Some manufacturers have been known to use this misleading marketing ploy.
How do I know which zoom is working?
You can see which zoom is in operation on your camera by one of the following methods:
1. Listening – You can usually hear the mechanics of an optical zoom in action. A digital zoom is silent.
2. Look at your lens in the front of the camera – is it moving in and out? -If yes then it’s the optical zoom lens in operation. No movement while you zoom usually means you are now using your digital zoom.
3. Look for the icon on the back of your camera that indicates that your zoom is in operation. This is usually a scale with a bar illustration from W – T. (W meaning wide angle and T meaning Telephoto.) Sometimes when you begin to use your digital zoom the color of this bar will change to red. And sometimes there’s an indicator on your camera LCD screen like a dividing line showing you that you are now in your digital zoom area. Check out your own camera manual to see which one applies to you.
I always suggest to my students, to turn off the digital zoom capabilities of their camera so that they will not be tempted to use it and hence loose quality. You can do this simply by going into your cameras set up menu and turning off the option for Digital zoom.
All in all a digital zoom really doesn’t add any value to your pictures with the exception of that one time where you really just want to see what’s going on really far away from you. You might be able to make out the scene but the resulting picture will not be too hot.
My advice – if you really need to get closer then firstly – Move Your Feet!