How To Make A Professional Softbox For Under $20
The side walls have a 45º angle. The upper part of the shape will be the length of your flash head, in my case, it's 3 inches. Next, repeat the process again to have the two large sides of the softbox. Afterwards, it's time for the short sides. The lower part is 25 inches long, and the upper one, the height of your flash head.
At this point, the angle of the sides is not so important, it's a little more than 60º, but to make it easier, simply use the length of the sides of the walls you made before. Now that you have the four sides of the softbox - two large and two small ones- , it's time to cut the cardboard carefully. Remember to leave a small amount of cardboard in the upper part, about 2-3 inches long, because that's where the flash goes. Cut every piece using a cutter, and place the finished ones aside.
Once you have everything cut, use some glue and cover every piece of cardboard with aluminum foil (but only one side). You can use aluminum tape along the borders to fix it more securely. This part will reflect the light of the flash, making it stronger and more powerful. Just in case, use two layers of aluminum foil, to ensure everything will stay intact for a long time.
Next, take the two short walls - those with the short part at the top - and tape two velcro straps on it. A large one, about 6 inches, and a short one, 2 inches. Also, staple it carefully and double tape it, to make it more resistant. These two straps will keep the flash from falling, and will hold it still. Once you have everything in order, it's time to assemble the softbox.
The order is very simple. First, take a large side, then a short one, then the other large one, and finally the remaining side. Tape it well and glue it, with large amount of glue and tape, just to secure every part, so that it won't tear apart. Remember to tape the upper part, where the flash goes, too.
A good way to check that it's properly built is to lift the softbox holding the upper part. If it doesn't move, then it's ok. If it's moving and unstable, add more tape until everything is secure. After waiting a few minutes, you can paint your softbox to make it look a lot considerably more professional. Use old newspapers and some tape to protect the parts you don't want to paint, like the upper hole.
I used black spray to make the process a little simpler. After it dries, add another layer of color, and then leave it drying overnight. Once you have the softbox almost finished, it's time to make the tripod adaptor. Use an L shaped aluminum bracket, and place the large side of it on the softbox.
Make some holes in the softbox, just in the middle of the short side. Then, using some screws and nuts, place the bracket and screw it on, making sure that it's stable and not moving. 10. To mount it, the easiest way is to insert the L bracket in the flash mount gently.
Now it's time to mount the diffusion panel, made of paper. Extend the paper roll on the floor, place the softbox face down on it, and carefully glue the paper to every side. You can also add more layers if you'd like to make the light much softer, and also more uniform and equal. Remember that the more layers you add, the lower the power of the light.
