Is strict objectivity theoretically possible? Objectivity is possible through analysis, prediction, and success. Which is to say you analyze the properties of something, say a planet and its motion, you predict where it will be, and upon receiving data on its coordinates in space which align with your prediction then that is an objective truth. The same can be applied to any empirical science and to state otherwise would imply the observation to be merely by chance, yet, we can accurately predict the functionality of matter, alter to our will, which necessarily requires objective perception.
Relative perception exists within things that do not actually exist in the universe, such as suffering, horror, and other sensations which are not what we perceive them to be, but are psychological phenomenons relative to survival, i.e. Animalistic perceptions. For example, you cannot predict whether or not with complete accuracy if someone will have an adverse emotional reaction to something, since the essence of which does not exist.