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

Oh I can begin an answer to this. In traditional hand animation, backgrounds are usually painted or drawn with a greater level of detail, because they presumably only need to be painted or drawn one time. The background is a separate piece of art than the character models. Characters, prop, and other moving items are drawn multiple times on multiple cellulose sheets, refered to as “animation cels”, that are laid on top of the background image to provide a foreground. These cels may appear brighter because they sometimes lack the fine detail of the background, a static image. It’s much simpler to draw the same character multiple times, so they tend to look simpler, with simpler brighter colors.