Q:

Onkelus translation of Gods name

Why does Onkelus usually translate the name Elokim as Hashem?
For example in the following pasuk (Bereshit 5:1):

זֶה סֵפֶר תּוֹלְדֹת אָדָם בְּיוֹם בְּרֹא אֱלֹהִים אָדָם בִּדְמוּת אֱלֹהִים עָשָׂה אֹתוֹ

is translated like this:

דין ספר, תולדת אדם:  ביומא, דברא ה' אדם, בדמות אלוהים, עבד יתיה

The first Elokim is translated as Hashem, and the second is left as it is.
What is the reason for translating Elokim as Hashem?
What is the reason for inconsistency in the same posuk?

A:

The sefer ביאורי אונקלוס here explains that the Targum Onkelos always translates the name Elo-him as Ado-noi so that it is clear to everyone that the posuk is talking about G-d, because the name Elo-him is also used in the Torah to mean judges.
The two exceptions to this are:
1) When the posuk says ה' אלוקים - two names of Hashem together, and thus people will not make a mistake in their understanding.
2) When it says בצלם אלוקים and בדמות אלוקים it leaves the name the same. He explains here in the name of the sefer אוהב גר that this is because Onkelos realized that it would be impossible to explain these expressions to the general population without being very lengthy, and thus it was better to leave them untranslated.

