Why is that in some animation styles things that are animated are brighter than the static background?

Question

As an example here’s a clip.

劇場アニメ『老人Z』（1991年公開）は沖浦啓之、黄瀬和哉、井上俊之、本田雄、松本憲生、磯光雄、森本晃司、福島敦子、今敏、森田宏幸、中澤一登、鶴巻和哉、飯田史雄、平松禎史など錚々たるアニメーターが参加している点も見どころで、特に沖浦さんが作画したこのシーンは何度観ても素晴らしい！ pic.twitter.com/UseSMawBLd

— タイプ・あ～る (@hitasuraeiga) March 8, 2020

At 20s you can clearly see what the background is and what are all the animated bits.

In: Technology

Answer 1

It all comes down to the moving elements being drawn differently than the background elements. In this old style of animation, the static backgrounds are typically painted, and can be very detailed. The moving elements are painted onto a transparent sheet (celluloid or cels) and overlaid onto the background. Cels aren’t as detailed as the background, and tend to use blocks of bright colour. The problem occurs when you need a part of the background to move. What animators would have to do is draw a cel over the background, to match as closely as possible. What you’re seeing is a cel, and not part of the background layer, which is why it looks different.