550EX,420,ST-2 and flash ratio -- underexposure

[tracyh]

I'm really struggling with underexposed shots using the wireless ETTL setup with my D60. I'm using the ST-2 on-camera to fire the 550EX main (group A) and the 420 fill (group B). I'm bounce flashing both flashes into an umbrella... the main being into a silver inside/black outside umbrella... the fill being white only. I'm also using a hairlight strobe that's triggered as well. I've tried all variations of flash ratio on the ST-2 and continue to get terribly underexposed shots. I end up having to crank the flash exposure up +2 (I'm using the FE on the camera... not the flash, though). I always use the FEB to get a reading, and don't recompose the shot. I'm using the camera in P mode with center-weighted metering, ISO 100, and flash white balance. I've tried changing the point of focus (and also switching to manual focus since I've read that this will help the ETTL use a bigger center-weighted area for determining exposure) to see if that makes any difference. It doesn't seem to matter. Then, at times, I'll get a crazy way-overposed shot in there. I cannot get a good, consistent exposure with this setup and cannot figure out what I'm doing wrong. I've also played with the distance adjustments on the flash, but my understanding is that I don't want that set since I'm bouncing it off the umbrella...?

The last thing I tried was to turn off the ratio on the ST-2. Now I get pretty consistent exposure.... but it's on the over-exposed side, and I end up having to adjust FE about -1. I adjusted the distance of the main and fill flashes and now shoot the fill through the umbrella instead of bouncing it. This seems to be okay... but I don't understand why I can't get the ratio to work. It's been a very frustrating experience... not to mention that my portrait subjects don't enjoy all the screwing around I end up having to do just to get a good exposure.

I've read that people have trouble with ETTL, but I've tried all the tricks mentioned to get it to work right, and it doesn't seem to help. Am I missing anything? Any help would be appreciated.

Thanks, Holly

[slejhamer]

How are you triggering the hairlight? Is it possible that the hairlight is firing on the ETTL pre-flash and thus messing up the meter readings?

[tracyh]

The hairlight is wireless, but not part of the ST-2/550/420 configuration, so I believe the hairlight is just triggered from the flash firing from the others. I would guess that it's firing after the 550/420 are, but I'm new at this, so I can't say positively. I can't remember if I tried the setup without it or not, but I could try that again to see if there's any effect....
Thanks-- Holly

[slejhamer]

I believe the hairlight is just triggered from the flash firing from the others.

That is true, but your flashes both fire twice when in ETTL. It is very likely that the first (pre-) flash is triggering the slaved hairlight, which may affect your metering (both ambient and flash.) In fact, some optical slaves can even be triggered by the ST-E2, as I found after much frustration. This may or may not be the cause of your problem, but is something to consider.

Try using M (manual) exposure settings, without the hairlight. I do this with my ST-E2 and dual 420s firing into umbrellas and have no problem with ratio control, though sometimes I will still need to bump up FEC by 1/3rd to 2/3rds stop.

Best of luck,

[tracyh]

Hey... thanks for that bit of info! I hadn't thought of that. I knew there was a pre-flash, but hadn't put 2 and 2 together. It happens so fast that you can't see it with the naked eye, so I just didn't think about it. The bummer is.... I think.... that it makes my hairlight un-usable.... certainly with the ratio, but maybe for ETTL altogether?

Thanks again for your help!

[slejhamer]

The bummer is.... I think.... that it makes my hairlight un-usable....


Maybe, maybe not. There are some high-end "digital slaves" that will ignore the pre-flash and even multiple pre-flashes, but I have not yet tried them. I have a Wein peanut slave firing a Vivitar 283 but I can not get it to sync with the 420s, though it is supposed to be the "digital" version.

It's possible that you could use a PC cord from your camera to the hairlight, but I don't know if you can use it at the same time as the ST-E2. Also, the strobe's trigger voltage could be an issue, and you'd probably want to invest in a voltage regulator ("Safe Sync" type of product) as insurance.

It is really tough to mix EX-series flashes with non-Canon strobes. In hindsight, I would have gone with a different setup entirely. :(

Still might. :wink:

[tracyh]

Yea... I'm starting to feel the same way! I would have never guessed that it would be so complicated to get appropriate lighting. Makes fixed flood lights sound better and better all the time (although, I'm sure my poor clients would disagree as the makeup runs down their face!). If I need to use the hairlight, I think I may just try using the current set up without the ratio... and do it the old fashioned way (physically move the fill light!). Then, perhaps I can just struggle along in manual mode and play with FEC. If I have shots that don't require a hairlight, I'll see if I can't get ETTL and ratio to play nicely together.

Thanks again for all your help....
Holly