I believe the only specific subjects we can be truly objective about, meaning uninfluenced by our emotions (just to reiterate the term) would be specific subjects we are entirely ignorant to. As an example, the subject of the Christian God to some random tribe hiding out somewhere in the world completely blind to us. That tribe is the only group of people in the world that could be objective of 'God' since they know not of him at all, everyone else, has some thoughts. Thoughts that are ultimately affected by our nature to judge.

This may be a stretch though, since objectivity really relates to the opinions of one, on a specific subject, but my argument stands that their opinion is objective because it's non existent.

In layman's terms: One can only have no emotional change in their opinions of something if they have no opinions of it at all.

Mathematical concepts, though created in the subjective mind, are observations of the nature of reality. Though our subjective senses were required to form, understand, or convey mathematical concepts, reason alone shows their truth. We can subjectively understand objective truth, and in this way we can be objective. It is possible to be objective about math.