building a twin flash set up

[birdfromboat]

I just bought a 580 II and am still a Noob at flash, LEARNING ALOT, ready to start accessorising now. In another thread, I asked for input on flash brackets with the intent of building one, I have worked up a version of the newton for single flash photography. Thanks to those that contributed ideas.
Now I am going to finally replace my ML3 ring flash for a ETTL II capable unit. Into the nineties! With the 580 as a master, what flash would you suggest for a slave? The 420/430/430II/580/580 II lineup leaves a lot of options to sort out, should I go for price, or will having an exact match for my 580II be worth the extra bucks? Does a slave flash mounted like a twin flash open up problems I am not aware of? What do I need to know before I start on this? THANKS, THANKS, THANKS.

[DDCSD]

I would just get a 430 and save the money. The 430 is very capable and is a great compliment to the 580. It is only about 1 stop less powerful and would be great for the times you want an on-camera flash but don't want he bulk of the 580.

[birdfromboat]

Thats how it would appear to me, unencumbered by deep understanding of flash. Is it worth the risk of buying a used flash like an older 430, or should I wait for the coming closeout sales and buy one when the 430II hits?

[PacAce]

What were you thinking of using the "twin flash" setup for? If used indoors, setting up the two flashes beside each other would not be a problem but it might be outdoors where there's nothing to really bounce the master command flashes back towards the slave. Using something like a Stofen with the top cut off might do the trick, though as that will allow a little bit of the master flash light to be directed sideways towards the slave.

[birdfromboat]

I plan to use the 'twin' set up for macro, in and out, product shoots for web, etc. I thought I would be able to turn the head of the units to face forward, with the bodies of the flashes turned in to each other so they could talk. Doesn't that work? I ASSUMED the 430 did the twist, does it not? ( I am so new)

[PacAce]

I plan to use the 'twin' set up for macro, in and out, product shoots for web, etc. I thought I would be able to turn the head of the units to face forward, with the bodies of the flashes turned in to each other so they could talk. Doesn't that work? I ASSUMED the 430 did the twist, does it not? ( I am so new)
For macro work, a twin head setup should work fine. I've used such a setup myself. The subjects are close enough that they can reflect the command signal back to the slave.

Re positioning the bodies of the master and the slave towards either other, that doesn't necessarily guarantee that they'll be able to talk to each other. What you need to do is make sure that the IR sensor of the slave is pointed towards the front of the flash head of the master (or any surface that can bounce the light back) because it's the flash itself of the master that sends out the command signals. But, again, for micro work, the master to slave communications shouldn't be an issue as long as the slave IR sensor is pointed relatively forward.

[birdfromboat]

thanks, I think I knew that about the light being the source of communication, and how optical triggers won't work with the TTL due to the preflash and a bunch of other stuff I learned by reading these threads but have never put into practice and therefore forgot. I will be buying a 430 as soon as the price drops or canon has a rebate, probably very soon. Outdoor stuff will probably only be VERY close stuff, bugs and such, should be plenty of master light reflected. Thanks again.