Poor exposure with umbrella- Need help.

[Bootlegger0173]

ETTL is not working properly when I use both flashes in master/slave configuration, although both work flawlessly when used seperatly.

Regardless of whether I bounce through or make it a shoot through, I am getting really poor results when using my 580EXII on camera and 430EX on stand. Tried power settings, as well as even setting my ratios to zero so that both would even fire full out, just to try to get a decent ammount of light, but no go.

No matter what I do, it still comes out vastly underexposed, regardless of shutter or ISO. Oh yea, shooting with manual camera setting, just like I do with one flash.

I figure that I am doing something basic all wrong but cannot figure it out. Any help would be greatly appreciated.

[Lotto]

First check if negative FEC is set on the camera or on the 580, in fact, set FEC to + 2/3 to get better exposure.

[Bootlegger0173]

I will try that but it is not set to negative. They both work very well seperatly, but just don't seem to be communicating correctly together. They both fire though.

I even set one 1 foot from subject, and nothing matters.

[mattograph]

Pics as examples?

[Bootlegger0173]

I'll have to load one. Might take a minute.

Replaced all batteries, but no help there. If it were an FEC problem then it would be there when only using one flash.

Both fire, but no matter what I do, I get severe underexposure, where I can barely make out a subject... even from right next to them. Hold on, I'll load one.

[linarms]

What's your shutter speed?

[Bootlegger0173]

Doesn't matter.

Tripod mounted everythig from 1/100 to 1/15, and I still get the same poor image. Here are two out of camera snapshots this morning using both flashes. 580 on camera as fill and 430 on pod as mainlight. Very dark. 430 was aprox. 3 ft. away as was 580. Subject range doesn't seem to matter either. Also included is a one-flash test snapshot with plenty of light. What gives?

http://i4.photobucket.com/albums/y141/Bootlegger0173/2Flash0ratioproblem-1.jpg

http://i4.photobucket.com/albums/y141/Bootlegger0173/2Flash0FECproblem-02.jpg

http://i4.photobucket.com/albums/y141/Bootlegger0173/Test-03.jpg

[Bootlegger0173]

Also, for these I didn't even use an umbrella, but just bare flashes pointed straight on.

It is like the ETTL is calculating way more light than is actually there and killing flash too early. My feable mind can't see to figure this out.

[Bootlegger0173]

I reckon that nobody has seen this before?

[Tareq]

I don't know, but is it really very difficult to use flash to expose and light portraits? i am not an expert but i was using my 580EX without any modifiers rather than that white built-in card of the flash and got good results.

[TMR Design]

The single flash shot is ok and it shows that the flash is firing and lighting the shot. I assume you have checked to make sure both flashed work find on their own.

If you remove the umbrella from the equation do both flashes fire and provide the correct amount of light? If you fire the flashes manually can you get the shot?

It definitely seems like E-TTL is messing up and I suspect it has to do with the umbrella. I could be wrong but I would test those basic things, let us know what happens and we can take it from there.

[mattograph]

Doesn't matter.

Tripod mounted everythig from 1/100 to 1/15, and I still get the same poor image. Here are two out of camera snapshots this morning using both flashes. 580 on camera as fill and 430 on pod as mainlight. Very dark. 430 was aprox. 3 ft. away as was 580. Subject range doesn't seem to matter either. Also included is a one-flash test snapshot with plenty of light. What gives?

http://i4.photobucket.com/albums/y141/Bootlegger0173/2Flash0ratioproblem-1.jpg

http://i4.photobucket.com/albums/y141/Bootlegger0173/2Flash0FECproblem-02.jpg

http://i4.photobucket.com/albums/y141/Bootlegger0173/Test-03.jpg

In the first two, are you absolutely sure they both fired? Neither pic has any light coming from the front, and the conspicuous absence of catchlights would lead me to believe that they did not.

It is very difficult to tell if a strobe fires unless you are staring right at it, when using multiple lights.

You are not going to want to hear this, but portrait work with ETTL can be very random. Since the camera "calculates" the light you need in each shot, it can second guess you and really kill your hit rate. I finally gave up and bought skyports, and my results are much more consistent.

In any case, my guess is that the on camera master did not fire in the first two.

[PaulBradley]

Yes, I also think they may not be firing - can the sensor on the front of the slaves see the master flash?

[DDCSD]

How far away is the side flash on these shots?

[coralnutz]

I didn't realized the ttl would work through or bounced off of the umbrella. I thought the flashe's sensors needed top "see" the subject to figure it out.

I only have sunpak 383s so don't really know anything about ttl.

[TMR Design]

Wherever the flash is pointed is what it 'sees'.

[DDCSD]

I didn't realized the ttl would work through or bounced off of the umbrella. I thought the flashe's sensors needed top "see" the subject to figure it out.

I only have sunpak 383s so don't really know anything about ttl.

TTL= "Through The Lens" The camera needs to be able to see what the flash is illuminating. The flashes need to be able to "see" each other to communicate.

[Bob_A]

The first two look like they were shot without the two flashes being completely charged, and the last one looks like only the 580 EX fired. I use the following setup, which is very similar to yours with excellent results:

420EX (slave) bouncing into umbrella (not enough power for shoot through IMO) as my key light
580EX II (master) mounted on camera for fill

I shoot using ETTL II and adjust the ratios to get the desired result (approx 3:1). Typically camera in manual at f/7.1, 1/125s, ISO 100.

This setup works very well for two person head and shoulders portraits or maybe 1-2 people full length, which is all I need.

I've had many results like the ones you've shown, which always happens when I'm not paying attention to ensure that the flashes are fully charged before taking the shot. Also, the 420EX charges much more slowly than the 580EX II.

[jrsforums]

Just to be sure....is your 580EX set up like this?

[coralnutz]

TTL= "Through The Lens" The camera needs to be able to see what the flash is illuminating. The flashes need to be able to "see" each other to communicate.

aha... that makes sense. :o

Thanks :)

[jrsforums]

Wherever the flash is pointed is what it 'sees'.

Indoors, particularly at this range, the bounce of the master should be easily seen by the slave.

It would be better practice to have the slave body (red plastic) be pointed to the master.

[DDCSD]

aha... that makes sense. :o

Thanks :)

:lol:

[TeeJay]

What ratios do you have set?

TJ

[Bootlegger0173]

No, it is reall not all that difficult to get enough light for a portrait, although getting the right mood can be tricky. That is why I thought that using them together would eliminate a reflector.

Thanks for all the responses. Lets see if I can hit them all here.

1. Flashes all had new batteries, and all were charged prior to firing.

2. Flashes worked fine seperatly.

3. Initial ratios were 1:4 (master being only fill and side light at 45 degrees as key light).

4. Final ratios for all above photos were 1:1 with no umbrella, just to grasp at some sense of light... to no avail. I'd guess that (have no meter) final photo would have been about another stop darker with umbrella attached.

5. both strobes were with 5 ft. of subject, and maybe 5 ft. roughly of each other, with 10 ft. white ceiling so should have been plenty of light going around to read each other.

6. Haven't ever tried these strobes on "manual mode" so don't know if they would overcome this or not.

7. Use ETTL all the time for portraits, as bounce and fill with great results, but this is the first occasion that I've ever tried to use these strobes together... although I've used other 580/430 strobes together in the past without issues.

8. I am not SURE that they both fired, but am sure that both pre-flashes did fire. I'll have to work that out.

9. I did not have the sensor of slave pointed at master, due to close proximity, but I'll try that and see if it helps.

Again, these seem to work very well as indvidual units, so I don't THINK that they are malfuntioning, but all my settings look fine, and they just don't seem to work TOGETHER, so I'm sure that it is something simple. I'll try pointing the sensor at Master, and keep yall informed, and if anybody has any other ideas, I'm all ears (or thumbs).

[DDCSD]

Were you firing the flashes straight on or bouncing? Sorry if you said that already, but I can't find it if you did.

[Bootlegger0173]

I tried both.

OK, update:

Turns out that the Master was not firing after all, just a pre-flash.

Something to do with the setup. I have not gotten it to fire. It was acting like it was set with the master "off", when it wasn't. It didn't do it consistantly but after changing it back and forth a few times it now will work, so in an effort not to mess it up again, I've decided to leave the flash always set in Master/ratio mode. I figure that as long as I'm not shooting with the 430 set for slave it won't matter. I see that it will still function normally if it is the only flash in the room like this.

Not an ideal solution, but other than accidentially triggering someone else's flash if in the vicinity, which is not going to be a problem usually, are there any other downsides to leaving it alone, as-is?