Why are Japanese translated subtitles non-conversational?

Question

I guess this question brushes along the lines of why "real Japanese" can't be learnt from drama/アニメ. I was watching the Dark Knight (2008) with Japanese subtitles and I noticed that the translations sounded like they were sentences written only used in a book/literature and not actual conversational Japanese. For example, there's a scene with the Joker in which he says

Joker: You see, in their last moments, people show you who they really are.

To which it was translated as

Joker: あれだな、末期においてな、本性を 晒け出すもんだ。

After consulting with my Japanese friends about how you would translate this to conversational Japanese, it just got me wondering, why are movie translations in Japanese done like this? I.e is it just for effect? Of course it depends on the era/setting but this is a modern film. What would be the difference/effect if conversational Japanese was used instead? i.e

Joker: 本性っていうのは最期に晒け出すもんだ。

Thanks

Answer 1

The translation you saw looks neither like the most natural translation nor like traditional subtitle translation practice. It's more like a translation that must make compromises with lip sync requirements (this scene?).

Basically, Japanese (commercial) subtitle translation is the art of summary.

清水 (1992), titled 『映画字幕は翻訳ではない』 (Movie Subtitles Are Not Translation), is a classical essay that depicts the work of subtitle translators. According to the book, Japanese subtitle translation has a rigid rule: You can only use 4 characters per second, and only display at maximum 14 characters × 2 lines at the same time (usually 10 characters per line). This is a tradition that has been established over time in that field to minimize potential hindrance to viewer's immersion.

People who watch movies with Japanese subtitles are presumably mostly Japanese, and they can understand the scene from the minimal subtitles with the help of the actors' performances. Some people do like watching them with curtailed subtitles and original acting (字幕派), and of course there are others who prefer natural Japanese voiceover (吹き替え派). This is an eternal controversy among Japanese movie fans. (Note: I rarely watch movies.)

So, in conclusion, it's not the best idea to learn Japanese conversation from most movie subtitles. Maybe you can transcribe/find a transcription of a voiceover, or go to video sites like YouTube (or here?) where people upload translations in hopefully more straightforward ways.