Quote Originally Posted by 2F/2F View Post
E-TTL is just as flawed as any reflected light meter. It will rarely give you the ideal exposure, just as with any reflected meter read directly off of the composition. Like all directly-read (meaning no tonal placement is performed), subject-reading (as opposed to incident light-reading) meters, it is inherently flawed in that it will not likely give the ideal exposure.

If the flash sensed the distance of that which you were focused on, knew what modifiers were attached, what kind of surfaces your were bouncing off of, how big the room is, etc., and altered the flash power to match that, your exposures for the subject at the plane of focus would be near perfect every time.

...but this is not how TTL flash metering works. This would be an impossible system to design for practical use. By the time you input all the variables, your shot would be gone.

You will get better flash exposures learning to adjust your flash power and/or f stop with distance than you will ever be able to get with any TTL flash meter....not to even mention incident flash meters....the best method for accurate flash exposures. They can be used in more hand held speedlight-lit situations than one would imagine (though not all of them).

E-TTL is a way to get some sort of workable exposure an average amount of the time for average people who who shoot average-toned compositions and cannot and/or will not do the above. It is not the way to get the ideal exposure.

Does this mean it has no use? Of course not! It just means that, like with any automated function, you have to be so aware of what it is doing, and always fudging it this way and that, that you are basically taking manual control of it anyhow! In this application, it can be a slight time saver, though you still need a manual thought process to get the best out of it.

It can also get you that quick, sloppy, ugly, lazy shot in a printable, though not ideal, way. IMO, this is its greatest use! Sometimes, having the freedom to not worry about being technically perfect can free you to snap pix at exactly the right time. An less-than-ideal exposure on a greatly-timed and positioned shot is better than a perfect exposure on a shot in which you missed your desired composition and timing.
I would have to disagree...I have tens of thousands of flashed wedding pictures that prove what you wrote otherwise. E-TTL is a fantastic feature and it is repeatable and consistent once one knows how it works. E-TTL2 is even better but not supported by any film EOS bodies, save for the very latest Rebel?

Since the flash meters through the lens, it is irrelevent for the camera to know about the flash modifiers, and the newer EOS flashes do take in consideration the distance from the subject, and it weighs heavily on the focus point the shooter chose. In addition the flash does not care if the it is bounced off the ceiling or wall, again because it meters TTL. All this conspires to create a flashing system that is right on perfect most of the time. The flash works closely with the chosen focus point and this conspiracy results in excellent exposure metering. In addition, the "input of all the variables" is mostly automatic, so the shot will not be gone by the time the camera workflow is done.

There are thousands of EOS pro shooters that rely heavily on E-TTL for millions of wedding and other types of shots with awesome results.

I love that one can slave many other EOS flashes and E-TTL supports this automatically, and E-TTL allows the photographer to focus his mind mostly on setting up the shot, composing it...manual flashing is old school and no longer needed save for the very specialized and rare shots. Little need for hand held light meters when using TTL bodies such as the Nikon's and the Canons (later film SLR models only).