Professional analysis; from imaging on optical zoom and digital zoom

In our contacts with many models of digital cameras appear optical zoom and digital zoom concept. For just getting started with digital cameras, and prepared to make the choice of the consumer, often only see both the ability to zoom in on distant objects, and not specific to tell the real difference between the two. This often leads to a specific purchase choice mistakes. In fact, optical

In our contacts with many models of digital cameras appear optical zoom and digital zoom concept.

For just getting started with digital cameras, and prepared to make the choice of the consumer, often only see both the ability to zoom in on distant objects, and not specific to tell the real difference between the two. This often leads to a specific purchase choice mistakes. In fact, the optical zoom is digital camera lens of a very important parameter, and the digital zoom the existence of differences in nature.

The difference is not only reflected in their works, in the final image, they will also have significant differences.

Only from imaging quality, optical zoom ratio digital zoom elite. But digital zoom because of low cost, widely also in consumer-level digital cameras equipped. Moreover, with the image processing technologies of enhancement, Digital Zoom effect has also improved, for example Sony SmartZoom digital zoom technology, is a more practical digital zoom technology.

In the face a large number of technical information, consumers seems more difficult, but in the optical zoom and digital zoom the how to make a choice between? here is difference, practical and specific problems such as choosing to do some simple statements, hoping to give everybody the purchase offer some advice.

Optical zoom and digital zoom for each principle

Optical zoom

To understand the principle of optical zoom, first of all let's see what lens imaging process.

In our junior high school physics class, the teacher will give us a magnifier Imaging tests, burning candles through magnifying glass will whiteboard clearly came out at the same time as the projection magnifying glass in the before and after the move, burning candles at the Whiteboard image size will change. This is both a camera and imaging of principle, the principle of optical zoom. The camera's optical zoom is by changing the lens focus position, in order to change the angle of the light entering the lens, so that the same distance of the camera object in the PC component becomes larger, or more distant objects can have to focus more clearly on the PC components.

Top camera imaging, simple plan, the optical zoom is by moving the lens the internal lens to change focus position, change the length of the lens focal length, and change the size of the camera lens to achieve the image zoom in and zoom out.

The previous figure, a red triangle long right-angled edges is the camera's focal length. When you change the location of the focus, the focus will change. For example, set the focus to move in the opposite direction of imaging surface, the focal length will get longer, the perspective will be smaller. In this way, the angle range of scenery in Imaging surface becomes even greater. This is the principle of optical zoom.

We always contact digital optical zoom focal length, it actually is on the focal length of length in the figure.

Such as the Canon A95 's 3 x optical zoom lens, focal length 7.8-23.4mm, referring to the focal length can change, in fact that is being taken to enlarge the scope of the object. While the equivalent focal length above jiaochang is formatted as a traditional 35mm camera focal length, and thereby become more intuitive, the problem is not in the scope of our discussions.

Digital Zoom

Digital zoom in principle to understand some of the more complex.

Now the mainstream technology, digital zoom is to use the image processor PC components in a region of the photographic unit of image information for separate zoom. However, the mere fact of zooming and image processing software for local amplification is exactly the same, without any value. Now, many manufacturers of digital cameras internal already contains image routing software, it can image zoom, detail loss at each pixel, peripheral characteristics analysis of pixels, and analysis of data obtained from the increase in the pixels surrounding pixels, in fact is the so-called "interpolation" Imaging. This to some extent reduces local amplification on the image quality of the image, but in fact, such a reduction is often very limited.

We are digital camera imaging structure simplification can get on the map.

In digital zoom, photo objects through the lens in the PC component projection image size does not change. Simply, the camera's internal software through the PC component of the central part, and the pixel for interception with built-in software to zoom in and interpolation, so as to achieve the effect of the image to enlarge. This process is that we often see in the digital camera with digital zoom.