Product shoots with ST-E2 and 2 580EX

[HKFEVER]

This is the first time I use ST-E2, 2 of 580EX for taking product shoots. But the result is not good:

1. Normally I only use 1 580EX for regular shoots and set the camera to M, A=4.0 -5.6 & T=60-125. This always give a good result for regular shoots.

2. But this time I need to shoot couple hundred product shoots, so I use ST-E2, and set the 1st 580EX 3 feet and 45degree from the left, 2nd 580EX 3 feet and 45 degree from the right. 350XT with ST-E2 (1 to 1 ratio) 3 feet from the product. All the 580EX are pointed 45degree upward with the built defector extended.

3. I use L588 for flash meter, set it to T=60, and get f=8.

4. So I set the 350XT to M, A=8, T=60, but the shoots is way under exposure (also I connect the 350XT to MAC G5 with Camerawindows).

Any suggestion.

I know I can keep trying different A & T value to get the shoots. But this is not the right way. I should be able to depend on the flash meter's reading not from guess and try.

Please find the attached drawing to show the setup I have.

[EricKonieczny]

Post a bad resulting pictures, it maybe shed some light on what needs to be done differently . No Pun intended

[HKFEVER]

This jpg shows the exact setup.

[HKFEVER]

When set to T=60, the flash meter read A=4.0.
So these 2 jpg are in ISO100.

[HKFEVER]

Then these 2 is with ISO400.

[HKFEVER]

I am sure the setting of the 580EX is OK, so.....

There must have something that I miss interpret the reading of the flash meter.

[Huckaback Photo]

Hi HK
this is pos a silly thing to ask or even sugest.
did you use the flash meter reflected reading or incident.
meter needs to be put where the product is facing the camera with the difuser or cone.
both camera and flashes would need to be set to manual.
sorry if I point out the obvious to you .
you could meter off the white but would need to adjust afterwards.
I'm just trying to help really.
best of luck
Martin (Huckaback Photo)

[CyberDyneSystems]

..or just crank up the FEC?

[HKFEVER]

Hi HK
this is pos a silly thing to ask or even sugest.
did you use the flash meter reflected reading or incident.
meter needs to be put where the product is facing the camera with the difuser or cone.
both camera and flashes would need to be set to manual.
sorry if I point out the obvious to you .
you could meter off the white but would need to adjust afterwards.
I'm just trying to help really.
best of luck
Martin (Huckaback Photo)

1. Meter is using incident and facing the camera.
2. I think the ETTL in the camera, ST-E2 or else is adjusting the flash amount in each shoot.
3. The camers is at M.
4. I forgot to set the Flash to M.

Thank you. I have to try it tomorrow.

But why the ETTL is limiting the flash power.

[SkipD]

If you meter a white background, any light meter will attempt to make the subject appear neutral grey. It appears that what you have is a situation where the flash metering in the camera (and/or in the flash) is doing just that.

In my opinion, you need to have this setup be totally manual. Set the flash units for full power - manual mode. Take incident readings of the light falling on the subject and set the camera accordingly. The lowest ISO setting should be plenty, and will give you the best image quality. If you need a wider aperture for depth of field control or something like that, then start lowering the output of the flash units (or move then further away). If you need more light, move the flash units closer to the subject.

If you need more diffusion of the light sources, get some light stands and adapters that can let you add umbrellas to the setup.

[HKFEVER]

..or just crank up the FEC?

Tried it, won't help.

[HKFEVER]

Fully manual in flash and camera is the magic word. I just tried it, and the picture is almost perfect, just a little bit over exporsure.


But is this the correct way?
Need to do a little fine tune on the camera or 580EXs' location.:lol:

[SkipD]

I would also crank up the shutter speed to the max sync speed that the camera allows (I just looked it up - 1/200th sec). The flash duration is far faster than the highest sync speed of the shutter for most cameras. A slow shutter speed will likely allow the ambient light to have an effect on your lighting scheme.

I do a bit of tabletop work with studio type flash units (AlienBees) and everything is done manually. This is the only way to achieve the control that is necessary.

Automatic flash setups are OK, but not for all types of applications. Your setup is especially bad for automatic flash control, because the large portion of the image is white. Automatic flash systems are expecting "normal" scenes with a range of reflectivity of the subject material.

[Huckaback Photo]

If your trying to use a flash meter it really has to be set up for what the meter tells you
you lose any ettl or indeed any auto (camera or flash)
what is sometimes strange with this sort of set up if you use one flash only and meter it then try the same with 2 flash heads, it will not double the output and yet you now in theory have twice the light (2 flash guns).
Just a sugestion to try.
take 2 more pieces of white card or the polystryrene you have there , put one piece behind each flash. now turn the flash heads around to bounce back off the card ignor the small deflector in flash, its only really for some catch light in eyes etc.
if you need to ratio the flash fire only 1 take a reading. now move the other unit further away and take a reading with meter and obviously you need a weaker reading .adjust distance of card reflectors to suit.
that set up will give you nice controlled soft shadow to 1 side or shadowless with both at 45 degrees, as you have virtually made a light tent.
one more point once set and metered with good exposure write it down and use the same next time as it will always be the same at same distances etc.
Glad to have helped you.
Cheers
Martin (Huckaback Photo)

[HKFEVER]

I tried with 3 flashs, and the picture will even darker.

It seems a main unit (not sure which one, camera, ST-E2, 580EX or 550EX) will check the flashs' power at the same moment of flashs' pre-flash and lower the total output at that same moment.

[SkipD]

I tried to find on-line manuals for your equipment in order to be able to help further, but had no luck.

Isn't it possible to put ALL the flash/slave equipment into fully manual mode? Each and every device probably needs to be put into manual mode so that no automatic exposure feature works. Then you should be able to measure the light with a handheld meter and set the camera's aperture accordingly.

[HKFEVER]

Yes, I can set every flash in Manual, but not the ST-E2.

And I tried it, the picture is great.