580EX II for available light portraiture

Once again I find myself in need of advice and what better place to turn than POTN!
I would like to do some portraiture using available light with my 7D (and eventually 5DMkII or MK III?) and to balance the available light, use a flash unit preferably diffused.
Will the 580EX II handle the job successfully or are there better flash units available?
I dont want to go with the whole studio light thing as I want the whole setup to be as portable and hasslefree as possible.
I intend to use a reflector (110cm 5 in 1) as much as possible as well.
If anyone has any examples they would be willing to share that would be great also.
Thanks all for any help.

580EXii with lumiquest LTP off camera

Off camera.

IMAGE LINK: http://www.flickr.com …/kontumpleiku/3​918161284/

The 580 is as good as anything else in the class of portable battery powered flash units, as it s one of the more powerful ones on the market.
Be aware that 'overpowering the sun' can be a challenge even for more powerful studio flash units.
And be aware that HSS is not the answer necessarily, as you will lose 2-3EV of power as soon as you turn on HSS and put the shutter speed faster than max X-sync speed. So using a faster shutter speed to 'dim the ambient' also manages to 'dim the flash' at the same time, and reduce its maximum effective range. And the HSS power loss continues to add on, for every EV faster shutter speed beyond X-sync speed.

As long as you're OK with using the sun as your key light, a 580 EX does a good job as a fill light (as HungV posted). If you're trying to use the 580 EX as a key light out doors, it just doesn't have enough power unless you're shooting very early morning or at night.

As Wilt described, HSS is useful in some scenarios, but is very limited for outdoor portraiture.

And a little bit of shameless promotion, I do have my 580 EX (Mk I) up for auction on eBay. Same power as the 580EX II.

If you can get a mod to change your title you might get more response as available light means without flash so using a flash for available light is contradictory. Like wilt said you cant overpower the sun with a speedlight, although you can do very good work using it for for fill on bright days to soften shadows. To your point about not using studio lights to be hassle free. To get good results using flashes for this sort of work you need to be able to control and tailor the light to your need and that will probably require moving it off camera and using a stand and softbox/umbrella. You cant get magic using a small diffuser regardless of the light source.

Sunshine is the absolute worst light to use in portraiture. It is extremely harsh, it is hot, it makes the client squint and leaves heavy distinct shadows which are the antithesis to good portrait lighting. The best outdoor lighting is daylight which soft and has very indistinct shadows. The 580 can be used as a main light outdoors provided it is taken off camera and softened with a light modifier. It can be used as a fill light on camera provided it is again softened and the ambient light is creating a good light pattern on the subject's face. I've seen hundreds of "fill flash" shots on the 'net which were actually just plain flash lit, boring shots that my six year old grandson could have done.

Benji

I've recently confirmed what Wilt is saying and as great as high speed sync can be, it has definite limitations.

Assuming you really want to shoot in bright Sun, if you want to underexpose your ambient light by 3 stops using speed speed alone and you're already at your max sync shutter speed then that means you lose 2 to 3 stops of light just by increasing the shutter speed 1 stop past max sync speed. Pushing shutter speed another 2 stops means that you've now reduced the output of your flash by 4 to 5 stops.

Well since you didnt really indicate outdoor or indoor low ambient light with a fast lens and whether you have the capability of using the 580EX off camera for fill either, but did mention a reflector, the below shot i recently did while testing several fast MF lenses wide open with only window ambient light and a 43" reflector might work for you:

MIR24-35mm f2.0

F2.0, ISO1250, SS 1/60, No Flash

Shot with 580EXii off cam with lumiquest ltp at around 4:45pm. Sunset in Miami is around 7:45. This shot had the sun high behind her and I think the 580 did a pretty good job of lighting her up.

I wouldn't go into HSS mode and use ND filter it I wanted to do wider aperture shots in sun lit situations.

I did use two 550ex in HSS mode with kacey beauty dish for the following though. Not sure what the FEC settings was. It was < +1 FEC.

Direct sun from behind.

Thanks for all the great responses guys and great shots as well, great inspiration.
Thanks all