雙鏡頭相機成智能手機新焦點

When it comes to smartphone cameras, the only number that has mattered for the past decade is how many megapixels they have. Now an innovation is arriving that makes the smartphone calculation even simpler: does it have one camera on the back or two?

就智能手機攝像頭而言，過去10年唯一重要的數字是它們的像素有多少。如今，一項讓智能手機的選擇更簡單的創新出現了：機身背面配備了一個攝像頭還是兩個？

A dual-lens system can bring all sorts of advantages to a smartphone that hitherto have been the preserve of standalone cameras. It can make autofocus faster and improve low-light photography. One of the pair can add extra zoom without compromising picture quality or adding bulk. The extra camera can also allow a wider angle for better landscapes and selfies. When combined with the right image-processing software it can add effects associated with expensive single lens reflex cameras, like a bokeh background or shallow depth of field, without needing to attach extra lenses.

雙攝像頭系統能夠將此前屬於獨立相機的各種優勢帶給智能手機。它可以讓自動對焦速度更快並改善低光成像效果。其中一個攝像頭可在不影響畫面質量或增大體積的情況下增添多倍變焦。額外的攝像頭亦可提供更廣的視角，以呈現更佳的風景拍攝和自拍效果。若與合適的圖像處理軟件結合在一起，它可以增添昂貴的單反相機可實現的效果（例如背景虛化或淺景深），而不需要安裝額外的鏡頭。

The next iPhone is expected to come with a dual-lens camera when it is released in September but Apple will not be the first to introduce this technology. Earlier this year, LG’s G5 phone added a wide-angle lens alongside its main camera while Huawei’s flagship, the P9, comes with a Leica-branded twin-lens system that boasts image enhancements.

預計9月發佈的下一代iPhone將配備一款雙鏡頭相機，但蘋果(Apple)並非第一家推出這種技術的公司。今年早些時候，LG的G5手機在主攝像頭之外增加了一個廣角鏡頭，而華爲(Huawei)旗艦手機P9搭載了萊卡(Leica)品牌的雙鏡頭系統，號稱能夠增強畫面。

I have been testing the Huawei P9 Plus, a larger model with a 5.5-inch display, while visiting the UK — the handset has not been released in the US.

我在訪問英國期間試用了華爲P9 Plus，它配備了較大的5.5英寸顯示屏（這款手機還沒有在美國發布）。

Pros and cons

利弊

As a phone, the P9 is a handsome device with a brushed aluminium back and solid build. The fingerprint reader on its rear is fast and accurate and leaves the front face clean and smooth. I appreciated the double sim-card slots — a fantastically useful feature, still too rare in high-end smartphones, that allowed me to take calls on both my UK and US numbers without carrying two devices. However, the battery, perhaps strained by the dual-sim usage, only just made it through the day.

作爲一部手機，華爲P9相當帥氣，擁有金屬拉絲的鋁合金背殼，結構堅固。機身背面的指紋識別器速度快且讀取準確，使機身正面顯得乾淨和光滑。我喜歡它的雙SIM卡插槽，這一功能非常實用，在高端智能手機中也仍然太少，它讓我可以在不用帶兩部手機的情況下，接聽英國和美國號碼的來電。然而，它的電池只夠用一天，或許受到雙SIM卡功能的拖累。

I was less of a fan of the P9 software. Huawei’s version of Android, which it calls EMUI, blings out the default apps in the same shiny gold colour scheme as the phone’s exterior, which I found tacky. That aside, the operating system looks a little too similar to Apple’s iOS, with EMUI’s square app icons and near-identical settings screen.

我不那麼喜歡P9的軟件。華爲版的安卓(Android)系統名爲EMUI，其默認應用也採用了手機外殼那種閃閃發光的金色配色方案，我認爲這有點俗氣。拋開這點，這款手機的操作系統看上去與蘋果的iOS有點太相似了，EMUI的軟件標識也採用方形設計，設置界面近乎相同。

Two lenses

雙鏡頭

In camera technology, at least, it will be Apple that is playing catch-up with Huawei. The P9’s two lenses do not change the angle or zoom but together create a single image with greater SLR-style depth of field, where the background is blurred to make the main subject stand out. One is a regular colour camera but the other captures images in monochrome, which is better for pulling out detail and depth.

至少就攝像技術而言，將是蘋果在追趕華爲。P9的雙攝不改變視角或焦距，但組合在一起帶來類似於單反的更大景深，背景模糊而主要拍攝對象突出。一個攝像頭是常規的彩色鏡頭，但另一個攝像頭捕捉黑白影像，能夠更好地捕捉細節和景深。

Taking regular photographs is no more complicated than with any other smartphone but there are lots of options. These include capture modes such as colour-saturated high dynamic range, night-shot and blemish-smoothing “beauty” mode to professional settings such as manual focus or white balance. All are instantly accessible by swiping from either edge of the screen.

一般的拍照並不比其他智能手機更復雜，但多了許多選擇，包括各種拍照模式（色彩飽和的高動態範圍圖像、夜景，以及消除瑕疵的“美顏”模式），以及專業設置（如手動對焦或白平衡）。所有這些選項都能通過從屏幕的任一邊緣滑動立即獲取。

Tapping the icon that looks like a camera aperture opens one of the killer features of the dual-lens camera, its wide-aperture effects. Touch the object on which you want to focus then slide your finger up and down the screen to adjust the image to the equivalent lens aperture. Ultra-low f/0.95 will blur the background almost beyond recognition and give a very narrow focus area, while the maximum f/16 will bring the whole scene into focus. This will be familiar to people who have used SLR cameras but the design — and instant preview — is intuitive enough for those who mainly shoot with smartphones too.

輕點攝像頭孔徑圖標，就會開啓這款雙鏡頭相機的殺手級功能之一——大光圈效果。觸摸你希望對焦的圖像，然後在屏幕上上下滑動手指，就能將圖像調節至等效鏡頭光圈。超低的f/0.95將讓背景模糊到若隱若現，創造出非常狹窄的對焦區域，而最高可達f/16的鏡頭將對整個場景對焦。這對用過單反相機的用戶來說將是非常熟悉的，但其設計（以及實時預覽）足夠直覺，讓那些主要用智能手機拍照的人也能明白。

Because this focus effect is achieved through software, the image can be tweaked after it is taken, should you decide the background is too blurred or the main subject indistinct.

因爲這種對焦效果是通過軟件實現的，畫面可在拍攝後調整——如果你覺得背景過於模糊或者主題不清晰。

This special aperture mode works best on portraits, with the focus automatically identifying faces, and on close-range objects such as flowers. When it works, which it does best with a simple solid subject, the photo can rival one taken with an SLR. Unfortunately, however, the software is not fully reliable and sometimes smudges parts of the image at random. I noticed this particularly when my subjects had fuzzy outlines or with the curved corner of a flowerpot.

這種特殊孔徑模式在拍攝肖像（對焦點自動識別人臉）和花等近距離物體方面表現最佳。它在拍攝簡單的固體物件時表現最佳，可媲美單反拍照效果。然而，遺憾的是，軟件並不完全可靠，有時會隨機模糊局部圖像。我注意到，當主題輪廓模糊或者花盆有圓弧彎角的時候尤其如此。

Verdict

結論

Like many technological firsts, the P9’s dual-lens camera is still a bit rough, or should I say fuzzy, around the edges. The special aperture effects do not work reliably enough for SLR users to leave their standalone camera at home but people accustomed to flat-looking images taken on smartphones will notice a difference.

與許多初始技術一樣，P9的雙鏡頭相機仍略嫌粗糙，或者我應該說有些模糊。特殊光圈效果還不夠可靠，足以讓單反用戶將單反相機留在家裏，但習慣於用智能手機拍攝單調圖像的人們將會注意到其中的不同。

Soon, many more devices will come with dual-lens cameras. As the software improves, a meaningful change in smartphone photography is coming into focus.

很快就會有更多帶有雙攝的設備問世。隨着軟件的改進，智能手機攝影將出現有意義的改變。