Optoelectronics
How to capture the Moon clearly without camera wobble
By Aaron Hu, division director, TDK Taiwan Corporation S
ome of today’s smartphones come with cameras with an optical zoom that features excellent magnification capabilities. Point your camera to the Moon and
you can capture sharp images of the Tycho crater, one of the most prominent ones seen from Earth. But how are these images taken at night and about 240 thousand miles (385 km) away, so clear? At such far distances, even the slightest camera wobble should make them blurry. Smartphone cameras keep evolving every year. Some newer models can shoot sharp images, just as you would expect from stand-alone digital cameras. The multiple-lens set up in the smartphone’s camera achieves this functionality. These cameras now have up to five lenses, each having different characteristics that enable an expanded range of photographic expression (see Figure 1). One of these is specifically for high-quality zoom photography.
Cameras that combine more than one lens with different focal lengths and fields of view allow you to zoom into a subject with less degradation in quality. These high-quality images can be taken with the use of optical zoom, instead of digital zoom. This is because the digital zoom technique simply magnifies a portion of the image that has been taken, hence the poor quality.
The effects of camera shake Smartphone cameras with high zoom capabilities can have as much as several tens of times’ magnification, enabling you to capture sharp images of even the craters of the Moon. However, this type of photography tends to result in blurred images due to camera shake. Because higher image resolutions make blurring more obvious, reducing camera shake is now a significant challenge for smartphone manufacturers.
Images taken with a long focal length 32 June 2022 Components in Electronics
www.cieonline.co.uk
Figure 1: Smartphone cameras continue to move toward multiple lenses - a ‘penta camera’ has five lenses.
make the subject appear larger, but the effect of camera wobble is amplified because of the long distance. Moreover, shooting photos in low light conditions, especially at night, often requires slower
Figure 2: Camera shake compensated for by moving the position of the lens along x-, y-, and z- axes.
shutter speeds, contributing further to camera shake. Even worse, taking photos at arm’s length or in windy weather conditions adds to the challenge.
How to solve camera shake The solution to this complex challenge is
the camera module actuator (CMA) used in optical image stabilization (OIS). The CMA fixes the camera shake with the actuator delicately moving the position of the lens to compensate for any slight movements. TDK has been working on OIS since camera technology first appeared on
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