Building a Softbox

Robert Edge · February 24, 2005

I've been thinking about buying a Chimera Video Pro Softbox, but there are two things that bother me. First, the price. Secondly, the fact that I'd like to be able to tailor the size of a softbox to the job. I'd like to bry building one. Suggestions about construction and materials greatly appreciated.

Bob Hayes · February 25, 2005

Here is a ridiculously detailed description.

1. Use foam core that is white on one side black on the other. A 4? x 4? sheet should be large enough.

2. Put the white side up.

3. Find the MID POINT of each side and put a light pencil mark. HINT. Measure 2? along the edge from each corner.

4. Use a straight edge to connect the opposite side mid point marks so as to make an ?X? in the middle of the sheet. This is your CENETER POINT.

5. Decide on the size of your soft box. For arguments sake lets say it?s going to be 3? x 3?.

6. Measure out three feet along each the edge of your sheet being careful to center it on your midpoint mark. That?s 1.5? on each side of the midpoint.

7. Now take the barn doors of the light you are planning on using. It really helps of you have a light in mind. Let?s say it is a Mole baby baby. Remove the doors from the light and open them. Measure the inside hinge length. On some lights you may measure slightly longer then the hinge. The idea is to measure the largest square you can fit inside the doors and as close to the light as possible when the doors are about 1/3rd closed. This is the length of the short side of your soft box. If it is too big the soft box won?t clip nicely onto the doors. Too small and it will cut into the beam of light. The size may be 8? on a baby but that is a total guess. (Note: When assembled the doors will be clipped to the outside of the soft box with 4 small clips. The doors will match the angle of the soft box sides.)

8. Now go back to your 4 x 4 sheet. Draw an 8? x 8? Box centered on the CENTER POINT. The sides should be parallel to the edges of the sheet. Draw a line connecting each corner of your 8? x 8? center box to the ends of the 3? pre-marked side sections. Each corner will send two lines out.

9. Carefully cut out the shapes you have drawn. The result will be 4 matching Isosceles Trapezoids with the base measuring 3? and the top 8? being parallel and the sides being the same length about 2?.

10. Take two sides white side up and tape them together with 2? white gaffers tape. Don?t make them to snug. Flip it over and tape the opposite side with 2? black gaffers tape. They should have enough flex to just fold together flat.

11. Repeat this step for three of the sides.

12. Place the Box Large side down and put the open side together. And Tape the outside with black 2? tape.

13. Fold the box so it is almost flat and tape the inside with 2? white gaffers tape.

14. Open the box and put it face down on the ground. If you have done this properly the box will sit solid and square on the ground. Place the semi open barn doors onto the back and close them until they sit snug. Clip the doors to the outside of the box and put the whole unit on your light.

15. Clip diffusion into the 3? x 3? front opening. You may find you get a center hot spot depending on the light you use. Open face lights seem to work better. If that happens tape a little diffusion on the inside of the box 1/2 way from the front and back.

16. If you were a little ?sloppy? in the taping of the box it will fold flat for storage. If you were extra sloppy it will fold on itself again making it even smaller.

My therapist wants me to stop but since Hunter Thompson died my office has been filled with bats and I can get them to stop taking my meds from me.

Edited February 25, 2005 by bob1dp

Glenn Hanns · February 25, 2005

Have you looked at the photoflex range?

Photoflex

Glenn

Matthew McDermott · February 25, 2005

Here is a ridiculously detailed description.

1. Use foam core that is white on one side black on the other. A 4? x 4? sheet should be large enough.

2. Put the white side up.

3. Find the MID POINT of each side and put a light pencil mark. HINT. Measure 2? along the edge from each corner.

4. Use a straight edge to connect the opposite side mid point marks so as to make an ?X? in the middle of the sheet. This is your CENETER POINT.

5. Decide on the size of your soft box. For arguments sake lets say it?s going to be 3? x 3?.

6. Measure out three feet along each the edge of your sheet being careful to center it on your midpoint mark. That?s 1.5? on each side of the midpoint.

7. Now take the barn doors of the light you are planning on using. It really helps of you have a light in mind. Let?s say it is a Mole baby baby. Remove the doors from the light and open them. Measure the inside hinge length. On some lights you may measure slightly longer then the hinge. The idea is to measure the largest square you can fit inside the doors and as close to the light as possible when the doors are about 1/3rd closed. This is the length of the short side of your soft box. If it is too big the soft box won?t clip nicely onto the doors. Too small and it will cut into the beam of light. The size may be 8? on a baby but that is a total guess. (Note: When assembled the doors will be clipped to the outside of the soft box with 4 small clips. The doors will match the angle of the soft box sides.)

8. Now go back to your 4 x 4 sheet. Draw an 8? x 8? Box centered on the CENTER POINT. The sides should be parallel to the edges of the sheet. Draw a line connecting each corner of your 8? x 8? center box to the ends of the 3? pre-marked side sections. Each corner will send two lines out.

9. Carefully cut out the shapes you have drawn. The result will be 4 matching Isosceles Trapezoids with the base measuring 3? and the top 8? being parallel and the sides being the same length about 2?.

10. Take two sides white side up and tape them together with 2? white gaffers tape. Don?t make them to snug. Flip it over and tape the opposite side with 2? black gaffers tape. They should have enough flex to just fold together flat.

11. Repeat this step for three of the sides.

12. Place the Box Large side down and put the open side together. And Tape the outside with black 2? tape.

13. Fold the box so it is almost flat and tape the inside with 2? white gaffers tape.

14. Open the box and put it face down on the ground. If you have done this properly the box will sit solid and square on the ground. Place the semi open barn doors onto the back and close them until they sit snug. Clip the doors to the outside of the box and put the whole unit on your light.

15. Clip diffusion into the 3? x 3? front opening. You may find you get a center hot spot depending on the light you use. Open face lights seem to work better. If that happens tape a little diffusion on the inside of the box 1/2 way from the front and back.

16. If you were a little ?sloppy? in the taping of the box it will fold flat for storage. If you were extra sloppy it will fold on itself again making it even smaller.

My therapist wants me to stop but since Hunter Thompson died my office has been filled with bats and I can get them to stop taking my meds from me.

<{POST_SNAPBACK}>

Ah those pesky bats. . .

Re: homemade softboxes; I'm all for DIY and I've seen some pretty impressive ones made that work well in a pinch, but none of them really hold up over time. And do you really want to be measuring foam core to get four matching Isoceles Trapezoids every couple of times out? Unless you've got an X-Acto knife fetish, and I know some people can't get enough of the things, I'd save my money and get a proper softbox. Chimera's are certainly expensive for a bit of cloth with velcro, some metal poles and a metal ring, but they work like a dream. I think you could buy a four season single person tent for less money, but then again it'd probably catch on fire. . .

I think the bats are taking my meds too. . .

Cheers.

Riku Naskali · February 25, 2005

I'd love to built a softbox, but foamcore is too expensive :huh:

Ram Shani · February 25, 2005

hi

you should take a look at what peritro did on farida

it's called the sputnik

ram

Edited February 25, 2005 by ramdop

Robert Edge · February 25, 2005

Bob,

Thanks very much. This will help a lot as I work out the design.

February 25, 2005

I did a bunch of these years ago for shooting stills with Speedotron strobes, and if handled with care you can get them to last a long time. I did mine with regular (all-white) foamcore and it worked out fine - the stuff that's black on one side wasn't available but it would have made the box look more professional. I actually used ordinary duct tape for the first few, again with no problems, but if I were to do it again I'd use proper gaffer's tape or something else.

Heat is always a concern - I had 650w modeling lights in my boxes but you'll probably be using hotter lights. Be sure to keep the bulbs well away from the foamcore. Provide lots of openings to vent heat unless you like visits from your local fire brigade. Having common sense is a big plus here - monitor your softbox (or boxes) to make sure you're not at risk.

For the face of the boxes I used trans-lum (or Flexi-glas, it's the same thing), which you can still buy here:

shop.store.yahoo.com/cinemasupplies/flextran.html

Buy a whole roll of this stuff - it's great - and use it to make great diffusers, or over windows to obscure the ugly view outside. It's durable and you just keep reusing it over and over.

Yes, foamcore isn't cheap, but if you get it at your local arts and crafts store you'll pay three times as much as you should. In any big city there should be a few professional art supply stores that will have a good selection at okay prices.

A professional box is FAR more desireable, of course (and less likely to burst into flames) but you can put together your own in whatever oddball dimensions you want for maybe $50 or so and if you get a year's use out of it, you're doing pretty well.

Phil Rhodes · February 25, 2005

Hi,

> Foamcore

Wouldn't that melt, catch fire, drip molten polystyrene everywhere, set off the smoke detectors, and generally cause consternation?

Phil

Bob Hayes · February 25, 2005

Hi,

> Foamcore

Wouldn't that melt, catch fire, drip molten polystyrene everywhere, set off the smoke detectors, and generally cause consternation?

Foam core is pretty heat resistant. I?ve never had it catch on fire although I?ve scorched it many times.

With regards to durability they have lasted for years.

I eventually bought 2 Chimeras and use them on video shots. They pack up more compactly and producers are used to seeing them. I still use my soft boxes when I need off size boxes. They are also a great way to test sizes before committing to the expense of a Chimera

Edited February 25, 2005 by bob1dp

Michael Nash · February 25, 2005

I'd love to built a softbox, but foamcore is too expensive :huh:

<{POST_SNAPBACK}>

$20 U.S. for a 4'x8' sheet...

Michael Nash · February 25, 2005

I've been using a small softbox lately for a special "beauty" fill/eyelight. This one is pretty small, but the basic construction idea can be used on a larger scale.

It's cut, folded and taped showcard (black on white), taped directly to the barn doors of a small fresnel. On one side of the box are two slots, one about 2 inches away from the light, the other about two more inches in. In the slots are custom made gel frames (made of popsicle stick type wood), with varying diffusion like 216, opal, and bleached muslin. I had this one made with the black side of the showcard IN, so that the remaining few inches of "snoot" in front of the last gel frame control spill a little better.

I have this unit under-slung on a c-stand, so that I can place the light right under the lens for some "flat" fill on the face.

I happen to have a picture I took the other day (you can't see the frame slots, unfortunately). Posing with his handywork is the constructor and key grip Brian Silva.

The gaffer of the show is Keith Morgan, inventor of the "Woodylight."

http://woodylight.com/

Bob Hayes · February 25, 2005

The nice thing about the style of soft box Michael is showing is that it really eliminates spills. As opposed to the Chimera style which are much softer but also much larger and less controllable. I shot a television series in South Africa several years back and we lit the standing sets with many of these boxes. They worked great.

Riku Naskali · February 27, 2005

$20 U.S. for a 4'x8' sheet...

38 euros for a similar sized sheet ;)

J.M. O'Malley · February 27, 2005

Here's the cheapest idea for a softbox you will find. It will fall apart after several weeks use, but that's okay, because you'll probably be finished with your project by then. I have used this softbox and it works great. Don't let your friends see it because they will laugh at you.

1. find a large box that is intact. go to a department store or someplace and ask them for one. they give them away.

2. put the bottom of the box back together, using a sturdy glue.

3. cut a small round hole in the bottom.

4. line the entire inside of the box with aluminum foil.

5. find a light bulb fixture and screw the bulb out. your best bet is a mechanic's lamp, the kind with the metal dish around the bulb. the dish will help with the heat from the bulb. place the fixture through the hole in the box, and then screw the bulb back in.

6. don't cut off the box tops because you will need them for barn doors. adjust them by using clear tape or string.

7. cover the front opening of the box with diffusion material, bakers parchment paper, or similar. DON'T use wax paper.

Don't use more than a couple hundred watts bulb, and make sure the box doesn't catch on fire.

You could also upgrade your box by using a plastic storage bin instead of a cardboard box, and using an outdoor grill cover as the diffusion. Make sure to consider what size box in relation to what coverage you want. If you can get a kitchen appliance box, like a microwave or larger, those work well. Total cost should be less than ten dollars. Twenty if you are not a savvy shopper.