Outer join with where conditions

Hello,

I wonder If I could move additional join condition from ON part of
query to where part.

For example instead of:

SELECT *  FROM
    booking_load AS bload
    LEFT OUTER JOIN dict_load_type_tsl AS load_tsl ON (
                    load_tsl.dict_load_type_id = bload.dict_load_type_id
                    AND load_tsl.dict_language_id = 'EN' ))

Could I write:

SELECT *  FROM
    booking_load AS bload
    LEFT OUTER JOIN dict_load_type_tsl AS load_tsl USING (dict_load_type_id)
WHERE
     load_tsl.dict_language_id = 'EN'

I thought that second query could be more 'optimizable', but gave no results.
Where is the problem ?

Best regards,
Michal