Blinking eyes with multi-flash E-TTL II setup: help

Hi all,<p>

 

I posted this on th elighting foprum but thinking it over, it is really an EOS

problem. And one that I cannot work around as far as I see, so I thought I would

ask here.<p>

 

I am shooting portraits in my basement studio, and I am using Canon speedlites.

I have read up all the web resources I cna find on E-TTL II and so on: I think I

have a good grasp of the reverse engineering done by others.

<p>

 

My typical setup:<p>

 

<ul>

<li>Fill light next to camera: 580EX as Master in group "A".

<li>Key light: 420EX as "B" slave into umbrella.

<li>Behind subject, lighting up only background: 420EX as group "C" slave.

<li>Master set to A:B C; with A:B ratio set as 1:4

<li>C set at -1EV or as needed to get background at right brightness.

</ul>

<p>

 

Look at the image below: the light works fine. Even if a bit unpredictable.<p>

 

But.. the problem: 80-90% of the pictures have some people (my wife and children

in particularly) blinking. This is due to the preflash. When they accidentally

do not blink, it is fine.<p>

 

<a href="http://www.willems.ca/temp/Blink.JPG">My son: very typical picture</a>

<p>

 

This is truly terrible. Last night I took 50 pictures of my wife; only 4 had her

with her eyes wide open (and 5 more with eyes half open: the rest with eyes

fully closed).<p>

 

I have tried all sorts of things (count; shine lights into eyes; fire fill into

umbrella, or dispense with umbrellas; you name it. But the same every time<p>

 

So how can I stop this? I only have two ideas and they do not work for me with

this equipment:<p>

 

<ul>

<li>FEL (Flash exposure lock) fires a preflash to measure and then flashes when

yuo expose later. But this does not work with "A:B C": when you use FEL, the

back light (zone "C") always fires at full intensity.

<li>Manual does not work: the 420EX's do not support manual settings at all.

</ul>

 

This is obviously a major issue that means I cannot use this Canon equipment in

my studio - unless you help me solve it. I am beginning to think, reading it

through everywhere, that my onlyu option is to dump all the Canon stuff and buy

manual strobes.

<p>

That would be a terrible indictment of Canon, if they cannot make a working

flash system. So am I missing something obvious? Any help or suggestions welcome.<p>

 

Michael

<p>

If your family has vary quick reactions you're basically out of luck.

 

Have you tried raising the ambient lighting so the preflash is less startling? I know hummingbirds react less to the preflash during bright daylight as compared to late afternoon.

My family seems to have very quick reflexes, yes. I don't: my self portraits are fine.

 

I have raised ambient light until just before it starts affecting exposure, but that is not enough to avoid this blinking. Not with my family anyway.

 

So, I am out of luck? That would be a pity, for such a lot of expense, and from such a well-known name as Canon. I am hoping there's some trick and Canon has not sold me a bill of goods.

This topic just came up a few days ago! Oddly, I use a multiple flash setup (ETTL-II) and it is

extremely rare to have the blinking eye problem. It happens only 1 out of 10 shots at the

most. So you family is unusual...

 

Have you tried the obvious: shout "here's the flash and hold your eyes open for a couple

seconds"? May not work with little kids but adults can quickly learn not to blink.

If I have read the post correctly, the problem is that "preflash" by the Canon strobes are used to actually calculate how much light to output? The preflash is strong enough to cause a blink, then the real flash catches the blink during the exposure.

 

1. Is there a way to turn off the pre flash and just measure the output with a flashmeter and set your aperture accordingly.

 

2. Use strobe equipment (ex. profoto, novatron, photogenic, alien bees etc) with a flashmeter to measure output , then set the aperture and you're good to go. You can use the umbrellas you already have.

 

Pardon my ignorance, but are many people using these little lamps in a studio setting?

Hi,

 

1) Yes, I have tried various versions of the "open your eyes now". Does not work .. especially with my wife. (Perhaps that should be telling me something!).

 

2) The analysis (prefaslh activity causes blink, real flash during exposure then catches that blink)is correct

 

3) I fear you are right and I need to buy all new speedlites. The 420EX does not support manual flashing. That is a crying shame since I paid rather a lot of money for these.

 

4) I have no idea how many others use these - they ar enot that little but Canon clearly eants them to be used in a studio setting. I bought them based on Canon's promise they would work... but perhaps you are right and I should nto have bothed with Canon flash. In that case I wish I'd have been told that before I spent the cash! :)

 

Michael

Puppy Face,

 

It did arise earlier. Michael posted earlier but there was no solution proposed.

 

I cannot come up with a solution that does not involve some change in equipment. However changing equipment seems more reasonable than changing family members ;)

 

The answer is FEL but you have to change one of your slaves for a 430EX so that you can set the back flash to M and use it to expose the background.

 

You can also try putting the back flash into group A to reduce the number of preflashes.

 

The problem is not unique to Canon it occurs with all the preflash wireless systems - Nikon has similar problems and Konica Minolta is a disaster.

I commented on a similar thread a few days ago. Same problem same setup.

 

A few things:

 

(1) WHEN YOU USE FEL, ETTL-II SWITCHES TO PARTIAL METERING ZONE FOR FLASH METERING.

 

This is why the "C" flash is firing at full power. "C" flash is not illuminating the partial metering zone, and therefore fires at full power. The camera tells you this by having the Flash Icon blink after FEL.

 

(2) If you don't use FEL. . .your exposures are messed up anyway, because the A and B flashes are evaluting both the foreground and background. Exposure to the foreground will therefore will be too high. . to the verge of blowout (ETTL-II won't let it blowout). Why is this not apparent? Because the A:B flashes are ultimated ratio-ed to the C flash. . and both flashes are dialed down to account for the "C" group (which does not illuminate the subject)

 

Proper exposure in this setup with normal ETTL-II is by luck, not design.

 

(3) Any flash not illuminating the subject should be fired in manual mode, because of what I stated above.

 

Best answer; Buy a 430EX for "C" group and fire it in manual.

 

OK. . you are using a 420EX as "C" group. It doesn't do manual. Get over it. You have a few other options:

 

(a) Use other lighting (like, a 100W bulb) to illuminate the background and forget about "C" group. Use your other flashes to illuminate the subject. YOU WANT TO USE FEL TO CONTROL EXPOSURE of the subject. (nice side effect. . .it prevents blinking)

 

(B) Be sneaky. Put the background flash into "B" group. When you do FEL, the background flash will NOT affect the subject or influence the other "B" flashes when calculated output. When you fire the shutter, the background flash will fire at the *same* power setting as the other "B" flash units. Ok. . .this results in UNKNOWN exposure of the background. Deal with it. It probably won't vary by more than a full stop under studio conditions. If you don't like the result. . .move the flash forward or back (but not in front of the subject), or use a diffuser or WHATEVER. you can do it!

All,

 

I like what I am reading. These are good suggestions all.

 

I think reading the above that perhaps one new strobe will do it for me (a 430ex).

 

>>changing equipment seems more reasonable than changing family members

 

It will certainly be cheaper: one new strobe vs one wife and two sons. Easy decision.

 

Of course I could just try drugging my family members so their reflexes slow down to something like my level. But failing that my plan looks like:

 

- Buy a 430EX and use that for the background

- Use FEL (I am entirely comfortable doing that)

- Then over time just buying all manual speedlites.

 

I think the "all manual" is the end solutino. Very odd that the Canon (and Nikon, etc) systems get in the way - they seem to make things worse rather than better. Gee, I wonder -speaking as an engineer- why there is no better solution they can come up with.

 

(One that immediately suggests itself to me is a user-defined delay between pre-flashes and flash. I would set that to a second or two, warn my clints there's going to be two flashes, and be done with it - while keeping all the benefits of an automated system.)

 

Michael

Best for me to get rid of blinky eyes is to have them keep there eyes closed or looking down, until I say open (and hit the shutter release).

 

Also works for outdoors so you don't get squinty eyes in bright sun, and even works for smiles (smile at the last second, so it doesn't look droopy or wierd).

 

Another thing to dry is to take two shots successively. I think if you keep the shutter half pressed between, you might not get another pre-flash, but I could be wrong.

 

Try these before buying new equipment.

Rear Curtain Sync? Dont know what camera you are using and if the option is available in multi E-TTL mode. If it is, turn it OFF.

I have thought about this abit.

 

Think about the problem you are trying to solve: You are attempting to balance FOREGROUND and BACKGROUND lighting from multiple units. But all you have to work with is the 35 metering zones of the camera. You don't even know which zones are background and foreground! Combine that with the fact that multiple units can be arranged totally at random!

 

Lucky it works as well as it does.

Jim,

 

<p>

 

<i>Think about the problem you are trying to solve: You are attempting to balance FOREGROUND and BACKGROUND lighting from multiple units. But all you have to work with is the 35 metering zones of the camera.</I>

<p>

 

Actually, this is where E-TTL II works quite well. The camera does this. It very cleverly balances back and front lighting by alternately flashing them and measuring response, knowing that group "C" only lights the background.<p>

 

The only problem is that all this preflashing (many preflashes, both for communication with zones B and C and for actually measuring each zone's light) causes the blinking blinking!

 

This is very clearly explained here: you may want to go to this link and open the first PF, the one about Canopn EOS Flash:

<a href="http://doug.kerr.home.att.net/pumpkin/#FlashRatios">http://doug.kerr.home.att.net/pumpkin/#FlashRatios</a>

 

<p>

(You've probably all read this, in which case, apologies)

 

Michael

Oh, and my cameras are a 5D and a Digital Rebel XT. Both work the same (E-TTL II)

Michael, have you tried to shoot at a faster shutter speed? I am assuming you have the sync speed at 1/200th, which to me should be fast enough for most people NOT to react. If you are shooting at slower speeds say 1/60th then there is the chance of blinking.

Just trying to help....

 

Cheers

 

Glen

Actually that is one thing I have not tried. I shoot at 1/125th and f/8. Will try 1/200th, which is the maximum the 5D can handle. Who knows, it might just make a difference.

Huh.

 

I had not seen Doug's article. Interesting.

 

I wonder where he gets the "Group C exposes the background only" stuff. And he does not discuss FEL for ETTL-II.

 

But assuming he is correct (Doug usually is), group "C" still will have problems if you use FEL -> because the "C" flash is not spreading light onto the partial metering zone. I would still recommend trying the "put the "C" flash into "A" group trick" (or just buy a 430EX . . .)

Huh.

 

I had not seen Doug's article. Interesting. Thanks for the link.

 

I wonder where he gets the "Group C exposes the background only" stuff. And he does not discuss FEL for ETTL-II. I will email Doug directly.

 

But assuming he is correct (Doug usually is), group "C" still will have problems if you use FEL -> because the "C" flash is not spreading light onto the partial metering zone. I would still recommend trying the "put the "C" flash into "A" group trick" (or just buy a 430EX . . .)

Actually the "C only illuminates the background" thing is quite clear:

 

- It is very easy to verify by testing (I've done it)

 

- The 580EX manual even refers to this - yes, in a silly footnote but it does say "C" should be used for the background.

 

And yes you are right, the 430EX for "C" is going to be the best solution I think: the new family would cost even more.

Well, I feel quite humbled. But. .. at least I learned something. And like I said. . .Doug is seldom wrong :)

 

_ _ _ _ _ _ _ _

 

The 580EX and 550EX manuals are explicit: "If you point group <C> towards the subject, the subject will be overexposed"

 

Note that flash exposure and ratio calculations are BODY functions, not flash functions. The 580EX manual is written specifically for ETTL-II, while the 550EX manual is implicitly for ETTL (since the manual predates ETTL-II cameras) Since both manuals say the same thing, I can only conclude that both ETTL and ETTL-II cameras work identically in this regard.

Hello,

 

This has been a great thread. I just purchased a second 580ex and tried my first portraits last night (grabbed the kids after a bath and snapped several shots). I was very happy with the results, considering these are my first attempts. I must say, I�m glad my family is SLOW�.. I didn�t have any blinking shots. I would like to also get a 430ex and try a background flash. If I am understanding things correctly, it (430 or 420) will work on the C group as long as I just snap the picture. Is that correct?

 

Also, I hope someone can explain this: In the manual, on page 41, it states that, �if RATIO A:B is set, the Speedlite in slave group C will not fire.� It sounds like you guys are doing this. What is the deal?

 

Thanks,

 

James<div></div>

Three Sunpak 555s or something similar running on AC is what I suggest, if you don't want to get into the best solution, which would be a set of studio strobes. They are cheap on the used market. Three of them would not cost any more than a new 580 Speedlight, and they are very versatile and easy to use...fully manual capable (easy to control) with an auto setting. Canon makes it a chore to use their Speedlights manually. Also, I'd use a flash meter, not your in-camera meter. If you want dirt cheap, the Sunpak 383 is less than $100 brand new and is just as easy to operate as the handle mount units...just not as much of a range and a lower guide number. If you really care about these portraits, you won't leave the decisions up to your camera, and for god's sake, you won't leave the lights in the exact same place for every shot like a Sears portrait studio!

 

Keith

What I am trying to say is don't even think about using automatic in-camera flash exposure for this situation. You are asking for technical problems and cookie cutter quality work.

 

Also, can't you turn off the preflash?

 

Keith

"Can you turn off the preflash".

 

Not in a multiflash setup. The camera does not know if there are flash units set remotely to fire ETTL or not. Therefore. . the camera will always fire command pulses to trigger slave preflash's. If the flash in the hot shoe is set to "M", that flash will not fire a metering preflash, but will still fire command pluses.

 

If, however, you have a single flash attached to the hotshoe -> and put that flash into "M" mode, then there will be no preflash.

 

note that any slave flash set to "M" will not fire a preflash.

 

Note that the ST-E2 transmitter fires a dim red pulse for the command pulses, which may be less intrusive (but any ETTL mode slaves will still fire preflash)

I read the article and see what the ratio thing was (I was really not thinking on that one).

 

Thanks,

 

James