Looking at Slavoj Zizek’s Book (2024) “Christian Atheism” (Part 18 of 33)
0195 Doesn’t that last point sound dramatic?
Well, the measurement of photons in the field of quantum physics is no different.
Once a photon is registered by a measuring apparatus, it2a is toast.
For example, the natural habitus of a photon is to fly as a superposition of states and waves2a. A particular scientific apparatus will collapse the superposition in the process of making the measurement. In other words, the photon is annihilated (or its habitus is forever changed).
0196 Here is a picture.

0197 On the content level, the normal context of what it is3a brings the actuality of a superposition of states or waves2ainto relation with the potential of the thing itself1a. The fact that I characterize the photon2a as a superposition of waves2a means that I, the investigator, have already replaced the noumenon2a with an imaginary of what the noumenon must be2a.
On the situation level, my imaginary2a as phenomena1b serves as matter to yield a form, a quantum measurement2bmade by my measuring apparatus3b.
0198 But, the realist in the back of the room shifts uneasily, saying, “Don’t you have it backwards? Shouldn’t the content-level actuality2a be labeled ‘real’ and the appearance that is conveyed by the measurement be labeled ‘imaginary’2b?”
0199 Yes and no.
Yes, surely, the noumenon is more real to the natural philosopher.
No, phenomena are more real to the quantum physicist, because observations and measurements of phenomena belong to the empirio-schematic judgment (what ought to be, secondness, in the Positivist’s judgment) and Peirce’s category of secondness characterizes the realm of actuality. In contrast, the noumenon (part of what is, firstness, in the Positivist’s judgment) associates to the realm of possibility.
Secondness (the realm of actuality) is more “real” than firstness (the realm of possibility).
0200 Contrary to Zizek’s discussion, the fact that the natural philosopher chooses the noumenon2a and the quantum physicist chooses its phenomena1b to receive the label, “reality”, does not mean that we have to choose between space and time. Rather, it means that we have to choose between the noumenon and its phenomena.
Well, which would I choose as the noumenon, space or time, or both, or neither?
Clearly, the quantum mechanical equations that model the standing waves of electrons around nuclei in atoms and molecules rely on both space and time as variables. Those variables go into equations that model data based on phenomena, not the thing itself. So, one might wonder about the status of space and time. Are they transcendentals or ontologicals?
0201 Certainly, space and time are not divine. But, they are not “not divine”, either. They are used in models that may veil the noumenon, so that a model (veiling its noumenon) [can be objectified as] its phenomena. Surely, that veiling makes what is of the Positivist’s judgment more palatable.
The other option is called “Copenhagen orthodoxy”. Niels Bohr (1885-1962), one of the physicists involved in the founding of quantum mechanics, read the writings of Immanuel Kant (1724-1804). So, he had a feeling that, as far as science goes, the noumenon is off limits. So, his solution looks like the following.

0202 Zizek agrees with later commentators, who say that this is the worst option imaginable.
But, Zizek has a caveat.
It could be worse.
0203 What about better?
Well, this examination already has made an advance, by labeling the content-level as the home to the imaginary noumenon. Here, the term “imaginary” does not suggest make-believe. Rather, the term means that the noumenon is to be approached as an image.
All sensations are like images.
Yes, for the most part, a sensation means that ‘something is present’. This is precisely how the natural philosopher encounters things. Things are dyadic actualities of matter [substance] form. Is that not like an image?
If matter is not present, then form is does not register with the sensorium.
0204 So, it makes no sense to place a sign over the imaginary and noumenon level that says, “This is not scientific, so please disregard.”