Portable Softbox?

http://www.bhphotovideo.com/product/62832/WEMAQ/REG/3750

The "Light Modifiers" catagory in this Lighting Forum has tons of threads about this subject... t

Photogenic softboxes are not made quite as well as others, particularly Chimera. However, they are very easy to set up and take down. The stays are held in place by Velcro flaps over the end. You simply bend the stays into the adapter flange to set up, and pop the flaps to relieve tension to break down. It can be a real challenge to undo stays without relieving the tension.

I have a 36x48 soft box that fits into a case about the size of an umbrella (sans flange, which goes in an air case with the flashes).

Lumiquest Softbox. Westcott Mini Apollo.

and a 580 isn't designed to be used in a softbox. I know people try it, and some people gang two into one box, but this is just further evidence that they are not really suited to large diffusing light modifiers. You'll need to put two in one box, which means a stand mounting system and this really negates the best attributes of the 580 flash... it's spontaneous auto-functioning abilities and small size/weight.

The little boxes (mentioned above) that velcro onto a shoe mount flash barely qualify as softboxes and are power hogs. Their effectiveness/value is doubtful.

If you actually want studio quality light, you'll need more power to fill a real softbox for use at middle apertures and normal portrait distances using an ISO under 400.

Maybe a black backed good quality reflective umbrella would be more efficient (productive) for you than a softbox, and probably faster and easier to use, too.. t

Maybe I missed it but I didn't see what camera you are using with the 580. If it's digital, then find the wall(s) or ceiling you can bounce the flash(s) off of. I use custom white balance with my Canon 20D's with a device invented by Ed Pierce and it works really well with most every lighting condition.

Re Tom B.,
Try an Ezybox from Lastolite. They are very compact (folds down like their collapsible reflectors) and it works quite good with the 550EX. With the 580EX it can just get better.
Here is a small gallery with some comparison samples. Those are my first tries, but is the only thing I've currently on-line: www.gerardmaas.com/gallery_642.html
Lastolite doesn't make an adaptor for hotshoe flashes, but as you'll see on the images, that's easily solved with a piece of structure metal from your local HW store.

-regards, Gerard.

Re: Tom M.
I think that portable flashes are very flexible. Of course they are not 'designed' to be used in softboxes, as their primary function is to beam some light forward, when on a hotshoe, giving that flat, harsh and awful light that we all want to avoid. But some units, like the 550/580 have capabilities beyond the 'dumb' light beam and can be used successfully in a wide range of situations. The wireless E-TTL in particular, can be very useful to achieve some good light on location. Their strongest point is portability, of course. You simply can't run around with a generator and monoblock in your hand.
Used in the right conditions, light modifiers on a 'hotshoe' flash units can deliver some great results. The main misunderstood point is that most people think that "one size fits all" and believe that they are going to cut every situation with an omnibounce. Ok. This thing starts sounding like I'm lecturing you, and that's not the point. Just want to say: give it a try. Just don't dismiss the option of using portable units on location.
-regards,
Gerard.

Lastolite Ezybox on location