I wanted a second strip softbox to do some more interesting portrait lighting set-ups so I decided to make my own. It takes a while and involves a number of steps, but I was very pleased with the end result. Prepare to spend a fair bit of time in front of a sewing machine as this has a lot of seams. All in all, I was able to do this in half a day & spent about $75 in materials. To buy one of these new you're looking at anywhere from $250-$500.
Step 1: Assemble the materials and tools
Materials used in this project include:
2 yards of heavy black nylon fabric ($12)
2 yards of heavy white nylon fabric ($12)
300 yards of heavy duty upholstery thread (Black/white) ($10 for two)
28' of Velcro (hook & loop tape) ($10)
3' of black nylon webbing ($3)
6 - 28" sections of fiberglass tent poles ($18)
Brown craft paper ($1)
** An important part to this is the ring that mounts to the poles and to your studio light/tripod. I have a few, so I didn't need to make one, and each ring is specific in size to each brand of light. Note that the size of the pole end should correlate with what ring you will be using **
Dremel tool (or hacksaw)
Step 2: Measure out the pattern on craft paper & cut
You will need two of each of the following (two in black nylon, two in white nylon):
Front/Back: Triangular "rangehood" shape (see diagram)
Top/Side: Rectangle with scoop cut (see diagram)
And two of the following (in black nylon):
Side/Top Panel: 25" x 8" side x 13" middle (see diagram)
One of the following (white nylon):
Diffusion Panel: 16"x58"
Step 3: Cut your fabric
Take the templates made in the previous step and pin them to your fabric. The templates also give you a chance to play with your layout to make the best use of your material.
Step 4: Mate the black & white nylon panels
If you can find a black nylon with white on the inside this step won't be necessary. I've seen some outdoors fabrics that have this, but not in a black (yet).
I ran a seam down the middle, then worked my way out from there. You might consider pinning the two pieces together so that they don't slip as you sew them together.
Also, at the bottom of the panels I added a velcro strip while finishing the edge - this will be used to attach the white diffusion panel in the very last step.
Step 5: Piece it together one seam at a time
As shown in the images, join the pieces together. When joining the Side to the Front/Back panel, use a strip of nylon (I used black, but would suggest using white if you have it) to create a 'tunnel' to later guide the tent pole. At the bottom of this tunnel, I added a heavy duty 2" wide piece of webbing (melt ends so they don't fray) - as this is one of the places that will get the most wear (accepting the end of the pole).
Step 6: Attaching velcro & adding the top panel
In this step you attach strips of velcro (or any other hook & loop tape) to the very top of the top panel - on the inside. Use the 'hook' part of the tape for one half, and the 'loop' part of the tape for the other half. This is used to allow access to the inside of the softbox, and be closed when needed to block out the light.
Step 7: Building the poles
I found some inexpensive fiberglass tent poles for $3/each. The problem was that they were too short at 28". For this size of softbox, you will need four poles that are each 36" - 36.5". I used the shorter ones, cut them with the dremel to size, then used epoxy to glue them together. I used small 1.5" pieces to 'plug' the ends of the metal sleeves - again with more epoxy. I notched the ends with the dremel so that the epoxy would have something to grab.
Step 8: Optional - carrying bag
Because I'm often shooting on location I like to have durable bags to store my softboxes in. I had some scrap pieces of black ripstop nylon, and some leftover 2" webbing. Roughly the bag is 9"x44" and could be made from leftover pieces of the nylon used for the rest of the box. I added a drawstring to keep it closed & plastic spring snap.