Does Nikon SLR have a built-in filter?

1. Nikon 39mm built-in rear plug-in gel filter bracket can be used for Nikon AF300 F4 D lens.

2. Nikon has released a patented lens technology, and OLPF is built into the lens. The significance of low-pass filter in lens is that it can eliminate lens aberration.

3. Some low-end entry-level SLR cameras have built-in special effects filters in software mode.