A Lensless Camera?

Cameras have been around since 1816 and a wonderful French inventor named Nicéphore Niépce. His camera had a basic lens that let light into a dark box onto a light-sensitive material.

This same lens makes an appearance in every camera today, from the high-quality ones for professional photographers to the smaller cameras in your iPhone and everything in-between.

In fact, the lens in your smartphone camera is one of the major issues in making the latest phone models even smaller and thinner because we’ve realised we can’t keep making them smaller and still be able to take the same quality of photos.

So enter the latest revolution, changing the game of 200 years of photography: the lensless camera.

Traditional cameras use lenses to focus incoming light onto film or an image sensor in digital cameras. This focussing requires the lens to have convex curvature and be thick enough to focus the light properly. Once the image is focussed properly, we can take a wonderful high-resolution picture to save to the camera roll.

 

But the latest generation of technology has a new idea. Why not get rid of the lens altogether and put the picture into focus afterwards?

And that’s exactly what they’re doing.

If you take a photo without a lens, you’ll just get a pixelated blob of vague colours and you’d never be able to photoshop it into anything even with fancy computer technology. Instead, lensless cameras have film with lots and lots of tiny circular rings (concentric circles) inscribed on it just in front of the image sensor.

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How a lensless camera works, from digitalrev

The carefully inscribed circles disrupt the light flow in an ordered pattern. The image is then processed and compared to a second image. The comparison of the two image produces Moiré fringes which can be analysed to determine the angle of the light that had entered the camera. A Fourier transform (that’s just a fancy math term for a complicated process that we don’t need to understand) is then applied to reconstruct the image.

That means the camera is actually just taking an image of light angle and pattern and then uses computing technology to produce an entire photo.

While there are also other types of lensless cameras, this particular system is up to 300 times faster due to dramatically reducing the amount of processing required. It’s also got potential to be marketed commercially possibly as early as next year!

 

Another exciting advance has also used whole glass windows as a “lens” of sorts, capturing the refracted light that is trapped and internally reflected inside a glass window to reconstruct images with the potential to be used in self-driving cars or even as a home security system in every window. This is based on similar principles as those in fibre optic cables that are now the best method of transferring wired data!

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A fibre optic cable with internally reflected light

 

While these lensless cameras can’t currently resolve images to quite the same quality as current lens cameras, they have reached 1/10 the resolution of an iPhone camera which is pretty good for such early stages! What’s more, research is continuing and progressing as these cameras are a likely candidate to take over the photography world. Additionally, lenses are more difficult to get ‘perfect’ in the right shape and focus and these cameras would be far cheaper. So welcome in the next era of technology!


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