Looking for a cheaper portable LED light for on location filming or photography well this is the $20 light. First you will need the items in the photo below. The poster board was $2.50 the wire was like $6.00 and the LED light strip was like $8.00 on amazon free shipping. Now I had all the tools if you have to buy the tools then this cost you a little more but not much. If you do have to buy the tools and battery holder then it might cost around $35.00
Step 1: Poster Board
Decide what size you want your light to be and mark the poster board with your favorite marking tool. I am going to base this off the size I made my light so I made my board 14"x 11-1/2" . Then cut out the poster board with a razor knife be careful not to cut your self. After you have the board cut out measure 1" make a line parallel with the 14" side then space you lines 5/8" apart. The draw lines parallel with the 12" side 1" inch from that side on both sides. These lines are to keep the LED strip lights straight.