Flash Exposure with EOS 1D Mark II

[Mike H]

Has anyone with a Mark II tested out the new flash metering system (E-TTL II)? I would be interested in any test results, especially if bounce flash were tested. Thanks.

Mike

[nosquare2003]

I'm interested too.

But can ETTL II be used in bounced flash?

[Mike H]

It would be of far less value if it couldn't be.

Mike

[nosquare2003]

I read from here:

http://photonotes.org/articles/eos-flash/#ettlii

[Mike H]

From the site that you cite ...

<<Distance data is not always used by E-TTL II. There are three very significant cases in which distance data is not used, aside from the obvious case when it isn’t available because the lens doesn’t provide it. These three conditions are bounce flash, macro flash and wireless E-TTL flash.

When you’re using bounce flash (ie: when the flash unit’s head is in basically any position other than full-on straight) then there is no way for the camera to know the distance the light took to reach the subject from the flash.>>

I disagree with this author. Distance data would be quite valuable in this situation. The metering system knows how bright the area at the focus point was before exposure and after the pre-flash was fired. It also knows the intensity of the pre-flash that it fires. And the system knows that you are in bounce mode, i.e., it can tell that you have the flash head pointed up. Using all of that information, it can calculate how the pre-flash was affected by the combination of distance and reflectivity of what it bounced off of. From there, the camera's computer can determine how much flash to fire to cause the object at the focus point to be rendered as a mid-tone given the shutter speed, aperture, and ISO setting in use.

One problem still remaining is that you may not be focused on a mid-tone. Still, if the system really works that way, it's some progress .... I hope. Of course, I'm speculating. We do that a lot here. :)

Thanks for the response.

Mike H