郭雪芙 Puff Kuo
2024 Aug
這個專案的製作從前期籌備就面臨了不少挑戰。在場景設計階段，我們與導演進行了大量討論，反覆確認道具配置與整體佈景的視覺邏輯。原本場景中規劃了大量植栽，以呈現人工島上的自然感，但考量到後製去背的複雜程度，最終決定將植物全數移除——密集的枝葉對去背作業而言幾乎是噩夢。
這次拍攝採用的並非標準的綠幕或藍幕，而是灰色背景。灰幕的去背本身就比標準色鍵困難許多，而更大的挑戰在於郭雪芙當天穿著全黑服裝、且本身擁有一頭黑色長髮。黑色主體對上灰色背景，兩者之間的對比極為有限，邊緣幾乎無法準確判斷，尤其是髮絲的細節處理，在整個後製過程中耗費了大量時間反覆修整。
可以說，去背是這支 MV 整個製作流程中最耗時、也最接近極限的一關。
在這個專案中，處理灰幕的經驗讓我們更深刻理解：在需要精確去背的拍攝中，綠幕與藍幕之所以成為業界標準，是有其不可取代的技術理由的。這次製作成為了一次紮實的實戰學習——關於色鍵的極限，以及什麼時候該果斷轉向逐幀手繪遮罩。
The production challenges on this project began long before post. During pre-production, extensive discussions took place around prop placement and the overall set design. The original concept included substantial greenery and plantation across the artificial island set — but these were ultimately removed entirely, as dense foliage would have made the keying process in post nearly impossible to manage cleanly.
The shoot itself presented an unusually difficult keying scenario. Rather than a standard green or blue screen, the background was grey — already a more demanding surface to key. The difficulty was compounded significantly by the fact that Puff Kuo was dressed entirely in black, with black hair. With dark subject matter against a grey background, the contrast between edge and environment was minimal throughout, and extracting clean edges — particularly around fine hair detail — pushed the limits of what keying could realistically achieve.
The keying process was by far the most time-consuming and technically demanding stage of the entire project.
The project also deepened our understanding of rotoscoping as a fallback discipline — and reinforced why green and blue remain the industry standard for keying. Grey screen, however aesthetically neutral it may seem on set, offers the compositor almost no technical advantage. What this production taught us, more than anything, is where the limits of keying lie — and when to abandon it entirely in favour of frame-by-frame roto work.
