SB-800 SU-4 mode

I contracted to do some portrait photography early December. I am

experimenting with the wireless lighting system using my sb-800 and sb-600. I

will likely purchase another sb-600 for the shoot.

I have set the sb-800 on my d200 as master, and the sb-600 as remote.

Everything works perfectly.

I also tried setting the Sb-800 to SU-4 mode, and got it and the sb-600 firing

off the built-in flash.

I was reading the manual and perhaps don't quite understand if there is more to

using the flash in SU-4 mode or not. Does that mode just turn the sb-800 it

into a remote flash that fires when the master flash fires or are there other

functions?

Any other suggestions you may have are appreciated.

Thanks in advance!

The SU-4 mode fires the flash when the main flash fires, and quenches it when the main flash shuts off. You can adjust lighting ratios and exposure by positioning the flash (power settings on the remote flash are ineffective in SU-4 mode - they work by quenching the flash not by adjusting the intensity).

TTL flash with multiple heads is a waste of time and largely ineffective. Set the flash position and power in manual mode, and use a flash meter to test the results. The camera should be in manual exposure mode too.

Listen to Edward. We're on your side, friend, but I will never understand the seeming

aversion to anything but these TTL and "intelligent" setups when using multiple flashes.

You have a DSLR that gives you immediate feedback, you're making your own light and can

control its levels at will, and you have several light sources availabel to you. Why would

you want the camera to try to figure this out when you can cut all the confusion out of the

middle and do it yourself in Manual mode?

For shots in our studio, I have one SB800 attached to the camera as a master, then four

big strobes and sometimes up to four additional SB28 speedlights. I shoot machinery and

depending on what the desired effect is, I will position the speedlights around on small

tripods. Or, if I want some internal accent light, I use the TTL connecting cable to slave a

speedlight inside the machine to one outside, whose SU4 will see the main strobes.

Though it sounds complicated, all you're really doing is manually adjusting the levels

betwen the various sources to get what you want. With the DSLR, you know right away.

Working with strobes in Manual mode should be compulsory for all photographers, like

knowing how to drive a standard transmission. Good luck with your project.<div></div>

There's no need for SU-4 mode here. That's an older optical slave trigger mechanism.

Set your D200 in Commander mode (custom setting e3). Set both the SB-800 and SB-600 in Remote mode, one in Group A and the other in Group B. Be sure all three (camera, 800, 600) are all on the same Channel. You'll need to pop up the D200's built-in flash, too.

Adjust the power of all three flashes from the Commander Mode screen on the D200 (that's the one you get when you select "Commander" in e3). If you set the built-in to "--", it won't (significantly) contribute to the exposure.

SU-4 mode is likely to work unpredictably (causing the SB-800 to fire when the master

preflashes happen, I think).

SU-4 mode simply emulates the SU-4, which is a nifty little flash sensor whose only job is to

fire the connected flash when it sees another flash fire, and quench when that master flash

quenches. All it does really is provide 'extension light', tricking the camera into thinking the

master flash is more powerful than it is. It's really nifty with an old plain TTL popup flash as

master, but it's probably going to cause you trouble in an iTTL setup.