ETTL Inside a Soft Box?

Newbie question - I just took delivery of a pair of PocketWizard ETTL triggers (MiniTT1 and FlexTT5) and a Westcott Apollo softbox. The 580EXII flash head mounts inside the softbox, shoots into the reflective back of the softbox, and then bounces back out through the opaque front material on to the subject.

So my question is, can I shoot ETTL with this setup or do I need to shoot manual? I'm guessing manual.

PocketWizard have updated their ETTL triggers so that the Pre-Flash is double the strength of the normal Canon pre-flash. But I don't know if it's enough to take a measurement through the Apollo softbox.

Anyone? (go easy on me, this is my first time shooting with a flash)

From all the workshops I have attended and read I think M is the preferred method for shooting in a studio as you are not going to be moving around and constantly changing light situations.
Leaving it in M would enable you, once you had the correct exposure for your shot to always have the same exposure.

I could be wrong, maybe someone with more experience might write something.

Actually I was hoping to use ETTL because I don't shoot in the studio much, I want to shoot on-location (indoors/outdoors). But yeah, I'm guessing I'm going to have to learn Manual model.

But I'd swear I'd seen somewhere that you can use ETTL flash inside a softbox with good results. Maybe with the PocketWizard AC3 Zone Controller. Hmmmmmm......

mitchman wrote in post #10973198
Newbie question - I just took delivery of a pair of PocketWizard ETTL triggers (MiniTT1 and FlexTT5) and a Westcott Apollo softbox. The 580EXII flash head mounts inside the softbox, shoots into the reflective back of the softbox, and then bounces back out through the opaque front material on to the subject.

So my question is, can I shoot ETTL with this setup or do I need to shoot manual? I'm guessing manual.

PocketWizard have updated their ETTL triggers so that the Pre-Flash is double the strength of the normal Canon pre-flash. But I don't know if it's enough to take a measurement through the Apollo softbox.

Anyone? (go easy on me, this is my first time shooting with a flash)

There no reason why you can't operate the flash in E-TTL mode as long as the preflash coming through the softbox is strong enough to be detected by the camera so that the it can determine the appropriate power level required for a good exposure. But if the detected preflash is attenuated too much by the softbox, the exposure might come out a bit on the hot side.

Thanks Leo. I was having the opposite problem today. There was hardly any output from the soft boxes at all. Could be that I don't know what I'm doing......yet.

I've used TTL inside lightboxes and in a Softlighter. Once you establish the correct amount of compensation it works great.

If you watch this PocketWizard video you'll see that the flash heads are firing into reflector umbrellas. They demonstrate shooting ETTL at around 3 minutes.

http://www.youtube.com​/watch?v=4HGyVhoW8iY

I'm guessing I was doing something wrong. I just couldn't get enough power out of the softbox to shoot a person sitting at the desk (in our office). The photo looked like I was just shooting with ambient light.

I probably just need to practice more.

mitchman wrote in post #10973403
Thanks Leo. I was having the opposite problem today. There was hardly any output from the soft boxes at all. Could be that I don't know what I'm doing......yet.

Can you try taking a picture of the front of the softbox with the exposure set so that we can see the light distribution going through the front diffusion panel? If you have the flash pointed towards the back of the softbox, then I'm thinking there's not enough space between the flash and the back of the softbox for the light to spread out. If that's the case, you can try pulling out the wide panel from the top of the flash head. Or use a diffuser like the Stofen OmniBounce.

Leo: You may be on to something. The flash is very close to the back of the softbox. I'm guessing that maybe it's too close.

There are 4 zippers on the bottom that form a "+" so you can fish the light stand through the softbox. I centered the light stand in the middle of the "+" and that puts the front of the flash about 3 inches from touching the back of the softbox.

TMR Design wrote in post #10973445
I've used TTL inside lightboxes and in a Softlighter. Once you establish the correct amount of compensation it works great.

What do you mean by "compensation"? Do you mean adjusting the Flash Exposure Compensation?

mitchman wrote in post #10973739
What do you mean by "compensation"? Do you mean adjusting the Flash Exposure Compensation?

Yes exactly. It's no different than if you were bouncing your flash of a wall or ceiling. You would increase the output to compensate for the indirect flash. TTL and the exposure calculations are based on the flash pointing at the subject.

TMR Design wrote in post #10973445
I've used TTL inside lightboxes and in a Softlighter. Once you establish the correct amount of compensation it works great.

+1
That's the nature of shooting with ETTL, I usually have to do some FEC. Eventually you figure out how much FEC is required for a certain modifier (sb, bd...) Also if you single point focus on a brighter or darker area of face for example, that'll have a significant effect on ETTL, so choose your single point focus carefully...

Jury is out on the matter of ETTL inside a softbox. Here is example of use of Metz 54MZ4 flash inside Wescott Apollo micro softbox (mine is an older version, and the flash fires forward into the white panel directly, rather than backward and bouncing against the back of the softbox to the white front panel)...


POTN posted test

Do a test with your flash! I'd love to see what happens with a Canon 580EX inside a softbox, compared to straight flash and bounced flash, and learn if the ETTL results are like mine or not.

I've used ETTL inside a softbox and also an umbrella with a ST-E2/430EXII.. Works quite well actually..

Although it works great in TTL why would you not want to use it in manual? I would always use manual over TTL if I could when the subject/s are in a fixed position and I have the time. I am assuming since you are using a softbox you have the time. More consistent I think. There is not much to learn about manual. If you are already adjusting FEC there is not much difference adjusting flash power manually. You are essentially doing the same thing. Are you using more that 1 softbox or light source?