You would usually say, "from different perspectives." In the first sentence the prepositional phrase "of different perspectives" is defining the word "issue" and changes the meaning of the sentence to say the different perspectives ARE the issue. Whereas, the second sentence means you have thought about the issue in different ways. You would need to use a preposition of place for this sentence. This may help... http://grammar.ccc.commnet.edu/grammar/prepositions.htm

To ponder something means to think about it carefully. When someone says, "After pondering..." they mean they have thought about it a lot before making their decision.