Literally, when we say actor (doer) focus sentence, it emphasizes the doer in active voice that usually begins in the sentence, while the object focus on the other hand emphasizes the direct object (or when the actor/doer is not specific):
to illustrate:
Boy (bata na lalaki) - SUBJECT
Tinapay (bread) - OBJECT
"Ang bata na lalaki ay kumain ng tinapay" ('The boy ate a bread'). = Actor Focus (Active Voice)
"Ang Tinapay ay kinain ng bata na lalaki" ('The bread was eaten by the boy) = Object Focus (Passive Voice)
from this sentences, regardless of what form you use or focus, they imply the same meaning.
Just to add a relevant info, an 'actor focus' sentences is also intransitive which of course can be a complete grammar even without a direct object. from the first sentence above:
"Ang bata na lalaki ay kumakain ng tinapay" ('The boy is eating a bread').
can be shorten to:
"Ang bata na lalaki ay kumakain" ('The boy is eating').
I hope this would help you.
:)