Exposure problems when using red filter in black and white photography

Filter addition should increase exposure; The sky is the theme, and the principle of white plus black MINUS should also increase exposure; How many files should I add? According to your customary standard above, you should add five gears. If you still don't believe me, do an experiment with a digital machine (be sure to expose files manually), put a filter in front of the camera, and then take a picture with the sky as the main body, and you will know for sure that you are right.