Using flash units

What i am looking for is sound advice on using multiplte flash

units. I presently have several eos cameras and a 550 ex, off camera

cord and sevral brollies and reflector. I would like to contenplate

using several in some of the situations which i encounter since they

are very portable. Do i have to stick to canon flashes such as the

420, 550 or 580, or can other manufactures flash units be used in

conjunction with my above and still be triggered and if so can this

be done by cord and what would i need. I thought more of cord because

sometimes i am outside and have heard that the optical triggers dont

always fire the flash. I tend to undertake a lot of portraiture and

besides illminating the subject i would also like to throw light onto

the location or backdrop, so how many flash units would you use for

this and in relationship to the foreground lighting what would be an

ideal ratio. By firing the main light into a brolly would this soften

the light enough to give pleasing images. can funits also be used for

hair lights and how would you do it. I also have a metz45cl4 which i

use in conjunction with my hasselblad but could some other units that

would be usable with the canon also be used with this and wahtis the

most cost effective road to go down. I would like a bowens portable

system but this is some time offf , so for now i will have to go down

the above route. If there is any advice that you can give me as

regards flash and its uses then please forward it to me with any web

advice on any site. I would really appreciate any help i can get.

 

Thanks Katie.

For this photo: <a href="http://www.photo.net/photo/3593288">http://www.photo.net/photo/3593288</a> and others like it in my portfolio, I have used a Photoflex adapter (can't remember the name or model number) and lightstand to attach an off camera flash to a small softbox and trigger it via a synch cable to provide a generous amount of fill-in light. The photo above was taken in the middle of the day during the summer with full sunlight coming from slightly behind the model so, what you're thinking of can be done. Your 550ex should be just fine for this. And yes, you are right, optical triggers can become pretty unreliable in daylight.

you can get by with one 550ex, but you mite find it a little hard outdoors in strong sunlight

or even thru brollies. two 550's mite be ok. the 550's use line of sight infrared triggering by

default and have a pre-flash that prob wont work with other brands. 550's are cheap used

now and have many useful manual settings for creating contrast between your foreground/

background.