Light Field Imaging: The Future of VR-AR-MR- Part 4: Jon Karafin (youtube, Lytro CEOpresentation)
Gordon Wetzstein: "Why should we care about light field displays?" (youtube,advanced knowledge)
The Lytro Light-Field Camera: How It Works (article)
Light-Field technology is here! Smart phone focusing after taking the shot (article)
兩則視頻，兩篇報(bào)道，了解光場(chǎng)技術(shù)！
翻譯一下article里對(duì)原理通俗的描述：
The technology is based on the idea of a light field, or "the amount of light traveling in every direction in every point in space," Ng says. While a conventional camera captures just a two-dimensional image of the light as it enters the camera, a light-field camera also captures the direction that the light was coming from.
這項(xiàng)技術(shù)（Lytro光場(chǎng)相機(jī)）是基于光場(chǎng)這個(gè)概念的，用Wu（創(chuàng)始人）的話來說就是：“從所有方向，穿過空間中所有的點(diǎn)，的光，的多少”（呵呵）。一個(gè)傳統(tǒng)相機(jī)記錄的是光進(jìn)入攝像機(jī)的二維圖像，一個(gè)光場(chǎng)相機(jī)更能做到捕捉光進(jìn)入的方向（天頂角、方位角）。
A normal camera has a lens, a sensor for recording the image, an aperture to allow a certain amount of light into the camera and a shutter to time how long the sensor is exposed to that light. All those working in concert create (hopefully) a well-lit single image. But in a light-field camera, there's an extra layer called a microlens array, which is placed between the sensor and the lens. This layer is composed of multiple smaller lenses, which allow the sensor to record more information about the incoming rays of light, including the light coming from different distances away from the camera.
傳統(tǒng)（數(shù)碼）相機(jī)有許多透鏡、感光元件、光圈（調(diào)節(jié)多少光進(jìn)入）和快門（調(diào)節(jié)曝光時(shí)間）組成。他們足夠拍一張好照片了。但是在光場(chǎng)相機(jī)的攝像頭和感光元件之間，多了一層叫“微型透鏡陣列”的東西。這東西不得了，它能幫助記錄物體離相機(jī)的距離（這樣就可后期加工景深了aka聚焦在不同位置。利用的是光場(chǎng)的額外信息，而不是僅僅靠算法，雖然還是加工出來的）
That extra information is the key to Lytro's trick. "In order to be able to focus after the fact, you have to collect the light field," Ng says. The additional recorded information allows software to manipulate the image, translating the stored information into what Lytro calls living pictures that can be refocused interactively, or even into three-dimensional pictures. The software essentially does the work of a physical camera, performing algorithms on the information collected by the light-field camera to mimic the physics used to focus a traditional camera.
更通俗的版本！：
Basically the idea of the so called **light-field **technology is that depth of field information is stored by taking a picture with arrays of pixels instead of single pixels.The resulting directional information can help a computer (or smart phone for that matter) calculate depth of field information after the shot has been taken.
光場(chǎng)技術(shù)，基本上就是用像素陣列而不是單個(gè)像素，來記錄方向數(shù)據(jù)。在拍攝照片之后，我們可以用記錄下的方向數(shù)據(jù)來計(jì)算景深（從而調(diào)焦距）。
關(guān)于magic leap是如何利用光場(chǎng)的， 非技術(shù)人員，無責(zé)任猜測(cè)：
不出意料的話，magic leap是對(duì)光場(chǎng)相機(jī)技術(shù)的逆運(yùn)用！
如上圖的光纖燈，如果把光纖末端對(duì)準(zhǔn)墻壁，你一定會(huì)看到一個(gè)五彩斑斕的投影。小時(shí)候家里也有一個(gè)這樣的光纖燈，宜家出品。把玩的時(shí)候（經(jīng)常玩壞就是了），我就在想，有沒有可能用光纖投影出一整副照片呢？
答案是肯定的：華盛頓大學(xué)的Eric Seibel一直致力于完成這樣的研究。（老實(shí)說在看到他的研究之前我早已忘記自己提過這樣的疑問-.-） Scanning Fiber Endoscope （youtube）（這是對(duì)光纖內(nèi)窺鏡的逆運(yùn)用）
繼續(xù)往下想，如果我們投影的不是二維圖片，而是經(jīng)過編程的四維光場(chǎng)（四維就是有四個(gè)變量來描述這個(gè)場(chǎng)），包含RGB、光強(qiáng)度和景深信息，是不是就能投影出一具3D物體了呢？
就像光場(chǎng)相機(jī)記錄的圖片可以合成3D圖片，反過來，電腦里的3D模型也可以經(jīng)過光場(chǎng)化，再投影在現(xiàn)實(shí)世界里。當(dāng)然，可能要經(jīng)過特殊的微型透鏡陣列！
即使是這樣，分辨率、壓縮和計(jì)算機(jī)感知（知道使用者相對(duì)3D模型的位置）仍然是讓人擔(dān)憂的問題，不過就magic leap的實(shí)力來說不在話下。估計(jì)今年(2016)年底會(huì)有大動(dòng)作，明年(2017)年底就可以當(dāng)年貨賣了:)。
這篇文章對(duì)光場(chǎng)投影提供了依據(jù)：
A Compressive Light Field Projection System——MIT
知乎上也有牛人提點(diǎn)：
Magic Leap 和微軟的 HoloLens 相比有哪些異同點(diǎn)？
