Diy camera filters. Trace your lens (or an existing filter) onto thin cardboard. For every filter you want to make cut 2 cardboard circles. Cut the same size holes in the middle of the circles so you have 2 rings of cardboard and place the filter you want in between.(I used cellophane for the yellow, red and green filters and an old 3d glasses lens for the polarized filter.) Glue the 2 rings together and voila!! You can fasten them to your lens with blue tack or tape.
This photograph demonstrates the effect that lens filters can have on a photograph in order to achieve the photographers desired effect- which would build the atmosphere and tone of the photograph and change the meaning of the photograph.