The wavelength of the infrared filter I bought is 720. Why is the photo taken red instead of magic white?

I guess I haven't played infrared photography on the first floor.

R-720 is really red.

Magic white is in post-processing

In fact, the method is very simple.

Just switch the values of the red channel and the blue channel. Please search for detailed methods.

Infrared photography

You can find many tutorials.