Who can tell me the conversion formula of depth of field?

let me explain to the first floor what depth of field is-depth of field refers to the distance range of an object measured in front of a camera lens or other imager along the axis of the imaging depth-of-field machine that can obtain a clear image.

the following is the formula for calculating the depth of field. Where: Δ —— allowable circle diameter f—— lens focal length F—— shooting aperture value L—— focusing distance ΔL1—— foreground depth ΔL2—— back depth of field ΔL—— depth of field Δ L1 = f δ L 2/(f 2+f δ L) (1)

back depth of field Δ L2 = f δ L.