“画面的溶暗”较为准确的英文表达可以是 "the gradual fading to darkness of the image" 或 "the slow darkening of the scene"。
“gradual fading to darkness” 强调了画面逐渐变暗、溶解于黑暗的过程,与“溶暗”中“溶”所体现的渐变感相呼应。
“slow darkening” 则侧重于描述画面缓慢变暗的状态,同样传达了“溶暗”的核心含义。