![]() ![]() It has been shown that the basic properties of light including amplitude, polarization, phase, and frequency can be flexibly controlled in a virtually planar surface by adjusting the geometry shape, material composition, and spatial arrangement of subwavelength structures, ,, ,. In recent years, metasurfaces consisting of subwavelength structures have shown great potential to trigger an optical revolution of Engineering Optics from 1.0 to 2.0, which benefits from its unprecedented electromagnetic properties not available in natural materials. Although the current advances in micro-nano fabrication technology have allowed significant integration of many optical elements, such as ultracompact multi-lens objectives, high numerical aperture (NA) microlens arrays, and other micro-optical elements, ,, these devices still rely on classical laws of refraction and reflection and the pixel size of these devices is generally about tens of light wavelengths, leading to limited optical performances. Although traditional optics has achieved great success, it still suffers from some inherent problems such as large volume, heavy weight, and single function, posing an obstacle for the urgent requirement of modern optical systems for integrated, planar, and multifunctional devices. Finally, we conclude with an outlook on future potentials and challenges that need to be overcome.Īs an effective expansion of the human eye, optical imaging systems like microscopes and telescopes open the door to the micro world and the macro world, wherein classical laws of refraction and reflection have underpinned the development of optical systems for hundreds of years. Thirdly, some representative functional devices and applications are surveyed. Secondly, some advanced methods for designing subwavelength structures with high angle robustness and high efficiency are discussed. Firstly, basic principles of wide-angle imaging using a single metalens are interpreted. In this article, we review recent advances of wide-angle metalenses, including operation principles, design strategies, and application demos. Recently, the emergency of meta-optics provides an alternative to constructing compact and lightweight large-FOV metalens through elaborated phase modulation within a flat surface, showing great potential in surveillance, unmanned vehicles, onboard planes or satellites, medical science, and other new applications. Expanding it generally relies on a combination of complex lenses, leading to a bulky and cumbersome system. As one of the key indicators of imaging systems, the field-of-view (FOV) is often limited by coma aberration. ![]() It’s not a lot, maybe just a millimeter or two, but if you’re going for the widest lens possible, it’s a tiny bit of a step back.Optical imaging systems, like microscopes, cameras, and telescopes, continue to expand the scope of human observation of the world. This, in effect, makes the lens slightly less “wide” than its focal length would imply. In my testing, you loose about 15% of the image width and height. So with one click, you’ve got a photo with straight lines. With many fisheye lenses, there’s an automatic correction possible in Photoshop. Essentially straightening out the bowed lines. So there’s a greater variety of wide-angle lenses available and a correspondingly wider variety of prices.Īs I mentioned earlier, with a bit of post-processing, you can get a fisheye to look like a regular wide-angle lens. Every lens company makes one maybe two, while making many wide-angle and wide-zooms. But that’s likely because there are just more wide-angle lenses available. Generally speaking, you can spend a lot more on a wide-angle lens than on a fisheye. There’s enough variation that it’s hard to say. “Crop sensors” like the super common APS-C size almost always zoom in just enough to create a rectangular image, where the same lens on a full frame camera would create a circle. If this is the case, fisheye lenses will be super wide, but rarely “circular.” In other words, they won’t create a circle of an image inside the regular rectangular frame. So instead, I’m assuming you have a crop sensor camera, like pretty much all cameras under $1,500, including DSLRs like the Canon 80D and Nikon D7500, or any mirrorless or Micro Four Thirds cameras like the Fujifilm X-T20. I would hope that if you’ve spent that kind of money, you don’t need a beginners guide like this. But we’ll get to that later.įor the purposes of this discussion, I’m going to assume that none of you reading this has a high-end full-frame camera. This essentially converts a fisheye photo to a standard wide photo. Barrel distortion is one of the easiest aspects to fix in an image in Adobe Photoshop or Lightroom, letting you remove the fisheye “look” with a click or two. While it would be easy to dismiss fisheye lenses as strictly a novelty, that’s not the whole story.
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