(Do point out if I got anything wrong along the way)
So I'm working through Jay Rubin's Making Sense of Japanese, and I've familiarized myself with the concept of zero pronouns, and his aversion to the "passivication" of active sentences.
From what I can gather, zero pronouns are used when the context makes it clear. Following that, Rubin warns against overlooking a zero pronoun subject, and interpreting an active sentence as a passive one.
For instance, when answering questions about what I had for lunch,
Original text: 犬｛いぬ｝を食｛た｝べた。
should be translated actively as
I ate a dog.
and not passively as
A dog was eaten.
A dog was eaten by me.
Because that would shift the focus of the statement from the agent on to the patient, by changing the subject from 'I' to 'a dog'. (Is this a kind of a semantic loss?)
Conversely, in a English to Japanese translation from an active sentence
I ate a dog.
to passive sentences such as
is there a similar loss in emphasis or topic focus along the way?
According to Earthliŋ here, "in Japanese, the passive voice leaves the focus of the action on the person performing the action", which I take to mean that the focus is still on the agent of the passive sentence, and not the subject. Is that interpretation right?
If so, does that mean that a passive Japanese → active English translation should be avoided because the initial focus is lost, but an active English → passive Japanese translation is alright?