How to remake a negative with a digital camera?

There are several ways to scan a negative with a common scanner. According to my friend, I haven't tried it, but I think it should work.

Scanning negative requires full scanning function, that is, reflected light cannot be used. In this way, you need a light source to scan the negative. Generally, a mirror can be used, and the mirror is placed on the negative. When the scanning head passes through the negative, the light beam hits the mirror and reflects back to become transmitted light, so that the contents of the negative can be scanned.

You can try it, and the effect may not be as good as that of a regular negative scanner.