Have you ever wondered how do film cameras know what ISO film you are using? In the day and age where you can change your ISO automatically or on every shot I take a look back at how a SLR registered the Films ISO.
If you take a look at a film canister there is a metal bar code called the DX code. Each code represents a different film speed. The camera then reads the code to set the ISO of the film.
This is an important step as if you set the wrong ISO in the camera you may not be happy with the results. The ISO tells the light meter where it needs to be so that you can get the proper exposures. If it is set wrong your images could be over or under exposed.
I hope you continue to enjoy the FroFilmProject Episodes.