In the camera, what is the length of the 8mm, 15mm, 24mm and 28mm lens? Is it the total lens length?

These data refer to the focal length of the lens. Generally, lenses smaller than 50mm are wide-angle lenses, lenses larger than 50mm are telephoto lenses and 50mm are standard lenses. Because its viewing angle is basically the same as that of human eyes, sometimes lenses larger than 45mm and smaller than 55mm are also called standard lenses.

The 8mm, 15mm, 24mm and 28mm you showed are all wide-angle lenses.

At present, the known wide-angle lens with minimum focal length is 2mm, and the real fisheye lens with maximum focal length is 3200mm. All of the above refer to cameras, periscopes, sights, telescopes and astronomical telescopes.

So these data are not the total length of the lens.