What does it mean to change the plane in astrophotography?

There is an infrared cut-off filter IR-cut on the surface of the photosensitive element of SLR camera, which has obvious filtering effect on the wavelength band (630-680nm) of the emission nebula, resulting in extremely low photosensitive efficiency of the emission nebula without changing the camera. Changing the camera is to remove the infrared cut-off filter and replace it with BCF filter with high transmittance to the emission nebula band. After changing the camera, the daily shooting will appear red, and the user-defined white balance pipette can be used to correct the white balance deviation in the early or late stage.

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In short, changing the plane is to improve the efficiency of celestial photography for some targets.