Today’s topic can be summed up pretty quickly. Digital zoom – bad. Optical zoom – good.
There two kinds of zoom on most digital cameras. Optical zoom adjusts the camera’s lens to give you a closer shot. Digital zoom simply magnifies the shot from the optical zoom, making the individual pixels look larger.
The advertised zoom rate (200x or more) is simply the optical zoom times the digital zoom.
Gus took some photos of the playground using his Kodak Easyshare C813 camera to demonstrate the various zoom options.
The LCD screen on your camera has a zoom indicator to tell you which type of zoom you’re using.
zoom indicator on a Kodak C813 camera
On the Kodak, you’ll notice 3 letters on the zoom indicator. “W” is for wide angle, this is as zoomed out as you can get. “T” is for telephoto, as zoomed in (or close) as you can get using the optical zoom. “D” is for digital, as close as you can get with digital zoom.
You’ll notice, the space between T and D is yellow, like a warning sign. This is to warn you that you’ll probably take some pretty bad photos if you go into the yellow area.
These indicators will vary depending on the brand of your camera. On my Nikon, there is simply a “W” on the far left, a “T” on the far right, and a little line in the middle. Anything between the line and the “T” uses digital zoom.
Here’s a photo Gus took of the playground using the optical zoom.
wide angle view of playground
This was shot with the zoom indicator all the way on the “W”. But Gus wants to take a photo of his friend up close.
close-up of playground using telephoto
He used the optical zoom with indicator on the “T”, or telephoto setting. But now he wants a really close shot. Let’s try digital zoom.
out of focus photo of slide using digital zoom
Whoa! What happened? Where’s his friend and why is everything blurry? He tried to take the shot, but everything looked like it was shaking all over the place when he looked at the LCD screen. The camera had trouble focusing.
Let’s see what happens if we take the original telephoto shot, zoom in and crop it (using photo software).
telephoto shot zoomed and cropped
You can see that the digital zoom on the camera basically took the telephoto one and enlarged it. You didn’t actually get any closer or more in focus. This version is not perfectly in focus, but that’s something we can work on in a future lesson.
If your camera’s settings let you, it would be a good idea to turn off the digital zoom because the photos come out so poorly. If you absolutely have to use digital zoom, always use a tripod.
Just remember digital zoom is good for seeing something up close (like binoculars) but not for taking photos of it.
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