Flash bracket and question on pttl metering

[danielchtong]

Re the image below. I think it is a pretty good and versatile setup. Thanks to Ed (Dawg) for his input. And I was about to pull the trigger.
But one question: how can the pttl flash meter if it is facing the umbrella (if the umbrella is on)?
If it cannot meter, would that mean I can only use the flash manually?
The set up is cool/neat in that the flash will be fairly high above the camera.
Any opinion would be appreciated on this close to studio setup

Daniel

[Dal1970]

As far as I know, the flash has nothing to do with the PTTL.

It should fire a pre-flash into the umbrella and the camera will set the right setting. I don't think that the flash has a sensor on it to measure the light.


When I use my macro setup, the flash is stretched out flat, and the pictures are correctly exposed.



Dal

[snostorm]

Hi Daniel,

Dal is correct that the flash doesn't meter anything, as the metering is done by the camera's metering system.

This setup possibly wouldn't work reliably if you were using the popup flash to trigger the flash in wireless TTL, because the flash needs to communicate with the body in a series of preflashes and the umbrella might not reflect enough for this to happen, but with a P-TTL remote cord, it should work fine, as all the communication between the flash and the camera body is done through the cord.

This setup looks cumbersome, but it should give you some great lighting.

Scott

[danielchtong]

Same idea as this one





snostorm wrote:

Hi Daniel,

Dal is correct that the flash doesn't meter anything, as the metering is done by the camera's metering system.

This setup possibly wouldn't work reliably if you were using the popup flash to trigger the flash in wireless TTL, because the flash needs to communicate with the body in a series of preflashes and the umbrella might not reflect enough for this to happen, but with a P-TTL remote cord, it should work fine, as all the communication between the flash and the camera body is done through the cord.

This setup looks cumbersome, but it should give you some great lighting.

Scott

Oops. There is a syn cord between the flash and camera except it is not shown . Nothing wireless at all.

Daniel

[danielchtong]

The above is normal set up. At the top of the bracket there is an umbrella mount for the flash to point backward.
There is no way that the preflash can be picked up by the camera metering system. So for this set up, all metering will be manual if I am correct.

[snostorm]

Hi Daniel,

I think you'll find you're wrong about that. I've bounced off a wall in back of me and ceilings as high as 12 ft using P-TTL, and it works fine, so there's no reason this setup wouldn't work well for you.

Scott

[danielchtong]

snostorm wrote:

Hi Daniel,

I think you'll find you're wrong about that. I've bounced off a wall in back of me and ceilings as high as 12 ft using P-TTL, and it works fine, so there's no reason this setup wouldn't work well for you.

Scott

Ok. Do you mean that the little preflash hitting the umbrella (at the back) and the subject (at the front) will be picked up by the camera for metering?
Hope it works out. I should be able to test it out in some local camera shop to see if that is the case. Thanks for all inputs




Daniel

[jachol]

Hi Daniel,

I thinkDal and Scottsaying the camera will measure any light reflected by the subject from the preflash, and then compute an suitable exposure. That's the way I understand it anyway, hope I'm right. ... Jack

[bigdawg]

It is a neat setup for doing on the spot Portraits. I think you'll like it Daniel! I decided to go ahead and do the CRD type flash and camera mount we looked at. I ain't a goin' to pay 800 bucks and tax for one though...Already started machining one to work with anything up to my bigma and K10D. Also work with my DX6490 Kodak and my cokin filter system. Now
I just need enough down time at work to do it! This is the one I mean!!LOL

http://reallyrightstuff.com/CRD/02.html

Dawg

[snostorm]

jachol wrote:

Hi Daniel,

I think Dal and Scott saying the camera will measure any light reflected by the subject from the preflash, and then compute an suitable exposure. That's the way I understand it anyway, hope I'm right.

Yes! -- the umbrella should be considerably more reflective (and will be closer to the flash head) than flat white painted walls and ceilings, and the preflash should be more than enough to allow the camera to meter. You may find that you have to up the ISO setting on the camera to get better exposures at greater distances, but you would have to do that anyway for any bounce situations.

Scott