550ex/420ex experts help!

[cowman345]

When using 550ex as master, and 420ex as a slave, is is possible to use manual mode on the flashes? (i.e. to get rid of pre-flash so I can use my light meter)

-dave-

[chris.bailey]

I think it is as I use a 550 EX sometimes to fire my studio flash setup. I use a Wein Safesync between the 10D and the 550 which takes out the contacts on the flash shoe that enables ETTL. Not sure if it works with another Canon Flash though.

[scottbergerphoto]

chris.bailey wrote:
I think it is as I use a 550 EX sometimes to fire my studio flash setup. I use a Wein Safesync between the 10D and the 550 which takes out the contacts on the flash shoe that enables ETTL. Not sure if it works with another Canon Flash though.

Chris, I'm a little confused by your set up. The 550EX will not emit a preflash when set to manual mode on the flash. You can set it using a flash meter just like your studio lights. You dont need to add a safe sync to disable the pre flash. To prove this to yourself, set the 550EX to Manual, turn on the camera. Push the FEL *button, there is no preflash. Switch the flash to ETTL, push the * button and the preflash fires. If you are worried about the preflash from a flash that doesn't have manual mode, like the 420EX, you can attach a Wein Digital Slave to your studio lights so they don't respond to the preflash. I use the Wein Safe Sync to attach a non canon flash to the hot shoe to guard against voltage spikes.

In regards to the original question, I just tried to do that and was unsuccesssful. I believe that is because the slave on the 420EX is not a typical optical slave that responds to a single pulse of light. It is designed to respond to a series of pulses from the 550EX in ETTL mode. The manual for the 420EX states on page 43 that if the master unit is set to M or Multi, the Slave unit will not fire. It has to be set to ETTL. That's that.
Scott

[Vegas Poboy]

Dave,
After reading your post I tried to shoot manual & it did not work, then i read Scotts comments and he is correct the 420 is Ettl only and it will not fire with the 550 in manual mode.
So far the only time I use the 550/420 combo is as a backdrop light or bounce it off a reflector or fill card and I have to play with the distance to get the correct exposure. After the holiday I plan on getting a sock or Omnibounce to stop down the flash but thats another day.

[cowman345]

Will a second 550ex fire as a slave if the both the master and it are set to manual mode? or do i require a slave trigger shoe?

-dave-

[chris.bailey]

[quote]scottbergerphoto wrote:

chris.bailey wrote:
I think it is as I use a 550 EX sometimes to fire my studio flash setup. I use a Wein Safesync between the 10D and the 550 which takes out the contacts on the flash shoe that enables ETTL. Not sure if it works with another Canon Flash though.

Chris, I'm a little confused by your set up. The 550EX will not emit a preflash when set to manual mode on the flash. You can set it using a flash meter just like your studio lights. You dont need to add a safe sync to disable the pre flash. To prove this to yourself, set the 550EX to Manual, turn on the camera. Push the FEL *button, there is no preflash. Switch the flash to ETTL, push the * button and the preflash fires. If you are worried about the preflash from a flash that doesn't have manual mode, like the 420EX, you can attach a Wein Digital Slave to your studio lights so they don't respond to the preflash. I use the Wein Safe Sync to attach a non canon flash to the hot shoe to guard against voltage spikes.

quote]

Not on mine it doesn't. If I use the 550 in Manual as part of my studio setup (sometimes useful) I can only sync at 1/60th. I prefer 1/125 but then it only syncs properly with the Wein in place. Assumed this to be the preflash.

[scottbergerphoto]

[quote]chris.bailey wrote:

scottbergerphoto wrote:

Chris, I'm a little confused by your set up. The 550EX will not emit a preflash when set to manual mode on the flash. You can set it using a flash meter just like your studio lights. You dont need to add a safe sync to disable the pre flash. To prove this to yourself, set the 550EX to Manual, turn on the camera. Push the FEL *button, there is no preflash. Switch the flash to ETTL, push the * button and the preflash fires. If you are worried about the preflash from a flash that doesn't have manual mode, like the 420EX, you can attach a Wein Digital Slave to your studio lights so they don't respond to the preflash. I use the Wein Safe Sync to attach a non canon flash to the hot shoe to guard against voltage spikes.

quote]

Not on mine it doesn't. If I use the 550 in Manual as part of my studio setup (sometimes useful) I can only sync at 1/60th. I prefer 1/125 but then it only syncs properly with the Wein in place. Assumed this to be the preflash.

Chris,
What do you mean it won't sync at 1/125? Do you mean it won't fire? What mode is the camera in? 1/60 is the default shutter speed when the camera is in Program or Automatic mode exposure and the flash is set to ETTL. I just put a 550EX on my 10D hot shoe. With the flash on Manual Flash mode, i put the camera in Tv and Manual. The flash fired at any speed between 1/4 and 1/200. I didn't try lower speeds.
Scott