Photoshop 의 Overlay Blending Mode

질문 : 포토샵 Blending Mode 중에 Overlay 란 무엇인가?

답 :
Multiply 는 두 컬러를 곱하는 것 즉 A x B 의 결과 C 를 취하는 것 (어두워짐)
Screen 은 두 컬러를 곱하되 (1-A) x (1-B) 의 결과 C 의 (1-C)를 취하여 밝은 쪽으로 만드는 것
Overlay 는 둘 다 해주는 것으로 어두운 쪽은 더 어두워지고 밝은 쪽은 더 밝아지는 것

출처 :
Overlay Blending Mode in Photoshop

Recall that multiply darkens images (white makes the underlying layer show through completely, darker colors on the blend layer result in a darker image) while screen mode lightens images (black has no effect, while lighter colors on the blend layer result in a lighter image). You may remember that one application was duplicating the layer and setting the top one to multiply or screen mode. Multiply resulted in darker areas getting darker, while screen resulted in lighter areas getting lighter. Overlay does both of these things at the same time, so if we take our standard rose image, duplicate the layer, and set it to Overlay, the contrast of the picture is turned up quite a bit.