setup with two masters & two slaves

I'm learning to take daytime indoor pictures (interiors, "house pictures") with a mix of flash light and ambient light, and it would
be very interesting to hear your recommendations on how to improve things.
Today, I have only one external flash (540 with diffusor), which I combine with the built-in flash (with a diffusor in front) set as
master since two light sources are better than one.
I'm not quite satisfied - especially in a big room or when two adjacent rooms are to be shot. I have considered radio triggers, but that means extra equipment that may/may not be reliable, more batteries that are exhausted at the wrong moment etc. Could I trigger the 540 (now set as master) from the built-in flash (still master) and just add one or two extra manual mode optical slaves (which will trigger from the nearest/strongest master) ? I realize that I need line of sight between the masters and the slaves. Since I'm using a pre-flash with the 540, the slaves must be able to handle that. Would I need Pentax slaves (360 ?) or are there cheaper alternatives (suggestions ?)? I only need manual mode for these.

Any advice is most appreciated.

Ragnar

You can use only one flash as master and the wireless (light pulses) range is about 4 metres.

One (and only one) master or controller (not both) can trigger as many slave flashes as you need.

Ragnar,
There are cheaper alternatives for the slaves. Some of the more modern slave sensors have the option of triggering on the 1st, 2nd, 3rd etc flash.
I seem to remember that there are some studio lights that have this option as well.

The trouble is that this approach ends up with piles of cables, batteries, power packs etc, and for shooting small rooms this may not be practical at all.

Also worth mentioning to shoot RAW for these types of shots. Katrin Eismann has a section in one of her books, IIRC, that shows a single RAW with mixed lighting (and hence colour temperatures) that was multiply processed in the RAW converter, and then hand blended in Photoshop with layer masks. Sounds complicated... but isn't And the results were superb.

Of course, the additional thing you can do (once you're prepared to go the whole way and blend images for white balance correction) is to shoot multiple exposures - you should be able to do this nicely without any flash guns Once again, it's a case of either hand-blending, or running through HDR style applications like Photomatix, Artizen, etc.

I'll see if I can rustle up a link to Katrin's work... (her website is www.photoshopdiva.com )

Matt

Ok. If we assume one master/controller (my built-in) and one slave in P-TTL mode (my 540) as the nearest gun, and further away two more slaves (in adjacent rooms, out of reach from the controller, but in reach from the 540). Is it possible to trigger the last two slaves from any strong enough flash that they pick up (the 540) ? They don't need to participate in P-TTL, just manual mode. If that is possible, I just need two more guns. No cables, battery packs etc. They just need to filter out the preflashes (how many is there ?). What is the cheapest flash gun that will do the job, is it a Pentax 360 ?
(Sorry if I have misunderstood you, but it's a bit confusing with all the terms : master, slave, controller, main flash etc).

Regarding hdr and photoshop blending - I do that all the time already. But now I want a quick way to get decent exposures from start.

Thanks for comments

I think it's getting clearer now
- Manual mode, no P-TTL.
- AF160 on camera and my 540 as "first" slave.
- Optical slave triggers with any type of power adjustable guns as "last" slaves.

Matt, why is it that the pop-up flash cannot be used to trigger "dumb slaves" ? And in my above scenario, couldn't the AF160 be replaced by the pop-up ? If not, why (since only one flash is needed) ?

Ragnar

Yes, of course. I figured that out later, but at that time I was already laying in bed...

Thank you guys for helping me out with this !

Ragnar

Thanks George. I'll keep that in mind.

Matt,

I was just struggling with that issue when I found your comment. I switched to Slave2, and now I can even fire the 540 from a flourocent lamp ! So I can save myself from the troubleshooting now an spend some time on Ebay instead.

Thanks a lot.

Ragnar

Erm, not necessarily I think Matt suggested a solution some time ago (a year or two - use a manual lens, set everything manual - preflash won't happen then. I tried it - and it worked quite well.