Lesson 6: Optical vs. Digital Zoom

ZoomWhen buying a digital camera one of the factors that you will be looking at is the power of the zoom function. People who are not very experienced in this field are starting to be a little mislead because manufacturers are often claiming a zoom function called digital zoom, or they add this zoom to the optical zoom so the total zoom to be greater. This is not so fair on the consumer as you will understand from this lesson.

Optical zoom is the real zoom. This function of a camera uses the lens to draw the image closer. When using optical zoom quality remains the same and the full resolution of the camera can be used on the zoomed image. The motion of the front lens moving outwards on a camera is the lens achieving a greater level of zoom.

Digital zoom is not a true form of a zoom function. The image doesn’t actually come any closer because the optics in the camera stay the same. The way the digital zoom works is the same as it does on your PC. The idea behind digital zoom is that it takes a portion of the image and expand that image to the full size of the image so the section you are looking at becomes bigger, not closer. The image does look closer because it has been expanded however all that has happened is that the image quality has been reduced.

Here is an example of optical and digital zoom:

Optical and Digital Zoom

So the digital zoom is the same as the zoom you can do on any software of digital image manipulation and it is also done with loss of quality. In conclusion the only zoom that is really important when you choose a digital camera is the optical zoom, the digital zoom if just for marketing purpose and in my opinion it’s useless.

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