The advantage of using this configuration is that the offset between the two lenses can be minimized, or even reduced to zero (so that both lenses shoot identical images), making the system particularly suitable for close-ups.
「實體 + 虛擬」的攝影方式，好處是可將兩個鏡頭的軸間距調至最小、甚至能完全重疊成同一個鏡頭，因此很適合拍特寫的近景。