Realism with respect to a class of objects is the view that the objects in the class are real in contrast to their being useful or convenient fictions. Science tells us that perceptual objects like trees and rocks are comprised of more fundamental conceptual objects like protons, neutrons, electrons, etc. and scientific realism is the view that such conceptual objects should, in the reductionist spirit, be considered as real as the perceptual objects they comprise. One may also be a realist with regard to "the past", "the future", "other minds", etc. However, postulating the existence and nature of some non-experiential "reality" that supposedly underpins the world of experience is not science but metaphysics, and has often led to erroneous conceptual models. Consequently I will stipulate my use of the word “real” in such a manner as to implicate anything that makes a practical difference in our lives - i.e. we might confer “reality” upon those objects (both perceptual and conceptual) that impact upon us in a predictable and repeatable manner, even if this means that we confer reality only on a provisional basis. I will refer to this as pragmatic realism to distinguish it from what I will call materialistic realism - the metaphysical doctrine that the “real” world is independent of any consciousness of it. Pragmatic realism makes no such metaphysical demand.
In pragmatic realism the moon is considered real because it affects our daily lives, whether or not it would continue to exist in the absence of any consciousness of it. On grounds of their explanatory power, protons, neutrons, and electrons are also considered real (note the technological advances that have been enabled by advances in particle physics), but there is a fly in the ointment here. We are inclined to consider “real” objects to have precise attributes at all times, just as we conceive trees and rocks to have. Adapted to our environment as we are, we believe objects to continue to exist even when nobody is looking at them. In the case of predators that have disappeared from view, our lives may depend upon that belief. So given the notion that there could be some particular duration in which absolutely nobody was looking at the moon, we still believe that the moon continues to exist with some precise size, mass, and location in space for that duration. This belief is supported by related effects that continue to be observed, like the moon's tidal influences upon the world’s oceans. A consequence of this is our innate conviction that all objects continue to have precise attributes whilst between observations, and that any inaccuracy in our knowledge of the attributes of such an object is a consequence of our inability to make sufficiently precise measurements upon it. But developments in physics have seriously challenged this conviction in respect of the continued existence of quantum systems whilst between observations (see appendix 1). This brings out the metaphysical aspect underlying that conviction and challenges this metaphysical position in the particular case of quantum systems, but it does not challenge the pragmatic belief in the continued existence of classical (i.e. non-quantum) objects. The consequences of classical objects going absent between direct observations would be far more grievous than that of, say, an electron going absent between interactions, provided that electron interactions remain lawful.
So, if by reason of innate prejudice we confer "reality" only upon objects that are conceived to exist even in the absence of any consciousness of them (materialistic realism), then panexperientialism clearly does not qualify as a form of realism. But if by reason of linguistic convention we confer "reality" upon those objects (perceptual and conceptual) that impact upon us in a predictable and repeatable manner, then subscribing to panexperientialism presents no obstacle to considering objects such as the moon, trees, and rocks to be real. However, quantum objects (such as electrons and photons) whilst between interactions might still fail to qualify as real, but this would be of no consequence to our practical lives and so would not undermine pragmatic realism.
Hilary Putnam has argued that, since the conceptual objects of science have tremendous explanatory power, it would be a miracle if these objects were not real. We should take care here to maintain our distinction between pragmatic realism and materialistic realism. I take the word "miracle" to indicate a violation of the consistent orderliness that obtains between constituents of the objective world - i.e. miracles are violations of the “laws of nature”. Any relationship that might obtain between the entire field of experience and whatever might putatively be “beyond” it (and responsible for the orderliness that manifests within it) is not a “law of nature”. The orderliness that obtains within the field of experience (i.e. between the constituents of consciousness) is a necessary precondition for the possibility of useful explanation, and the human propensity to seek explanation transgresses its limits when it seeks an account of why such explanation is possible at all. The upshot is that panexperientialism is realist in respect of other minds and is consistent with pragmatic realism in that everyday objects like trees and rocks may be considered real. It may also be considered consistent with scientific realism given that conceptual objects such as galaxies and atoms may be considered provisionally real (i.e. real unless and until new evidence comes to light that would call that ascription into question). Consequently we should be suspicious of any impulse to reject panexperientialism on grounds of our innate materialism.
There is, however, a credible argument that undermines the view presented in this account, and this is the most convenient place to consider that argument. Special Relativity Theory predicts that a system of photons has zero mass when the photons are all travelling in the same direction, but that the system has non-zero mass when the photons are not all travelling in the same direction (see Appendix 2). If this is indeed the case then, just as tidal influences on the world's oceans provide evidence that the moon continues to exist when nobody is looking at it, so the acquisition of mass in systems of photons would provide evidence that photons continue to exist between their interactions.