Flash modeling in manual mode in a wireless slave setup (550ex, ST-E2)

[fulvio_n.]

Actually I own a 420ex and a 550ex on a Eos33/Elan 7 camera. I use

the 550ex to wireless control the 420 speedlite in ettl mode. Since

420ex has no manual mode I have always to use it in automatic ettl

mode. I rarely use the manual mode on the 550ex since I can't use it

away from the camera. I'm planning to buy antother 550ex and trade

the 420ex flash for a ST-E2 transmitter. In this way I'll be able to

use two flashes away from the camera and in manual mode with a flash

light meter. I have a couple of questions:

 

1) The ST-E2 mounted on the camera does allow flash modelling by

pressing the DOF button on my camera? (I can do that with the 550ex

mounted on the hotshoe: when I press the button both the 550 and the

420 fire the modeling light which allows me to see the shadow casting)

I want to know if the two 550ex will fire the modeling flash as I

press the DOF butten on my camera with the ST-E2 mounted on. It is

very important for me to know this.

 

2) The ST-E2, although it's not a flash itself, actually fires an

infrared preflash while in ettl mode to determine the correct

exposure of the slave flashes. If I use my two 550ex in manual mode

can be the preflash firing avoidable? I ask that beacuse if I want to

use some non-eos flashes activated by other flashes, firing the ettl

preflash of the ST-E2 could activate it before the real non-ettl

flash. I don't think that ST-E2 has a "manual mode", but maybe a

solution to the problem could be isolating the ettl contacts on the

hotshoe under the ST-E2. Is it safe to do this?

 

3) I've read that ST-E2 has a limited wireless transmissions working

range, about 3-5 meters. Is it true? On my 550ex manual I've read

that used indoor the wireless infrared signals of the Flash bounce on

the walls and this may improve the quality of the signal. Is it the

same for the ST-E2? I plan to use the ST-E2 mainly for indoor use.

What it could be its real working range?

 

Thank you very much

 

Fulvio

[jimstrutz]

2) The communication preflashes of the ST-E2 will fire your other non-E-TTL flashes if they are optically slaved. Isolating the extra pins on the ST-E2 will probably disable it entirely, but even if not, without the preflashes it would no longer trigger the 550EX.

 

Triggering the other lights might be possible with a digital slave device that either ignores the preflashes or delays firing after it senses the first communication preflash from the SE-E2.

[bill_goldman]

As for your no.1, the modeling light feature will work with all 550EX and/or 420EX slaves on the same channel.

[bill_goldman]

And as for your no.3, the ST-E2 has adequate range for most any indoor application. Outdoors requires line-of-site between the ST-E2 and slaves. You may have to test it to find out what a realistic range actually is.

[fulvio_n.]

<i>"Isolating the extra pins on the ST-E2

will probably disable it entirely,

but even if not, without the preflashes

it would no longer trigger the 550EX." </i>

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Damn! Are you sure about this? Why the preflash is necessary even in manual mode? By isolating the 4 ettl pins the ST E2 wouldn't just fire one flash (without preflashing) and tell the other flashes (all of them) to fire? I thought that in manual mode the ST-E2 would work like a flash pilot to trigger all other Canon EXs(and only those; while the 550ex flash would have triggered the non-Canon flashes)...

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Is there some third-part flash that allows modeling flash like 550ex, ettl, full manual mode, and can be connected either wirelessly or safely by cheap flash universal wires without isolating any pin or doing strange things?

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I'd like to have a portable set of flashes without spending a lot and the flash modelling feature is very handy to me to predict the shadow casting on the subject. Wireless and automatic ettl is useful outdoor, while indoor (eg studio photography) I don't care about wires and like to meter manually every light.

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<i>"Triggering the other lights might be possible with a digital slave device that either ignores the preflashes or delays firing after it senses the first communication preflash from the SE-E2."</i>

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Where I can find such item? Can they be built easily? Are there any instructions on the web to do it?

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thank you

[fulvio_n.]

Many thanks for your informations.

[jimstrutz]

Digital optical slaves are made by Wein and others. You can order them from B&H Photo, or Adorama. Go to the Photo.net home page and click on one of the links at the bottom of the page. That way, if you buy, Photo.net will get a little money for leading you there.

 

I have no idea how you could make them, but if you were an electrical engineer, I would not think it difficult to devise an adjustable delay to an existing optical slave. From there it would just be a matter of trial & error testing to find out how much delay worked with the ST-E2.

 

however, I really don't see the point of using Canon's wireless E-TTL system with a manual flash system. The Canon parts are way too expensive to use this way, and they just simply don't want to cooperate with manual flash systems. There are work arounds, but I don't think the effort and expense is worth it. If you need a truely portable, fast setup system, get the Canon wireless stuff for all of it. If you can take the time to meter manually, save yourself hundreds of dollars, and get a manual system.

[fulvio_n.]

<i>however, I really don't see the point of using Canon's wireless E-TTL system with a manual flash system. The Canon parts are way too expensive to use this way, and they just simply don't want to cooperate with manual flash systems. [...]If you can take the time to meter manually, save yourself hundreds of dollars, and get a manual system.</i>

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I think I'll solve my problems using Metz flashes. I tried the 54mz4 (I don't know if in US is named in the same way, anyway it's the Metz top "cobra" flash head). Does everything I need and it's less expensive than Canon 550ex and there's no need to buy unuseful accessories (like the ST-E2). Also I could use those flashes with a Rollei MF camera. Among all others, they have an interesting feature: the modelling lamp is triggered on the flash and it is not activated by camera (like Canon EXs).

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Bye