Difference between digital camera lens and photographic objective lens

What is the specific definition of "photographic objective" you said? This doesn't seem to be an appropriate term. For example, in the optical path of a biological microscope, there is an objective lens (objective lens) that contacts the specimen slide and an eyepiece (eyepiece) that contacts the human eye, and so is a telescope. Contact with the eyes can be called eyepiece, and the front can be called objective lens. It can be said that the objective lens is relative to the eyepiece, and there is no objective lens without the eyepiece.

A SLR camera has a monocular optical viewfinder, and the lens in the window that the photographer looks at can be called an eyepiece, so the lens in front of the camera can be called a photographic objective (in fact, no one calls it that, but it is more called a camera lens). The digital camera with LCD camera has no eyepiece, only the front "lens". It is far-fetched to call it an objective lens, so people call it a camera lens. That's all.

Compared with the camera lens, the telescope's objective lens sees an enlarged virtual image from the eyepiece, and the camera lens should be a reduced and inverted real image on the focal plane. The SLR viewfinder also sees an upright virtual image from the eyepiece.