e-ttl vs automatic

[joey1234]

Can any one tell me what the difference is between the 2?

[Lotto]

A little more detail for your question would help :) Like between a EX Speedlite and a Vivitar 285HV?

[40Dude6aedyk]

There is no difference if using a Canon camera and a Canon flash of recent vintage.

[Curtis N]

With E-TTL, the camera does the metering through the lens, and tells the flash what to do. It uses a pre-flash to determine the required flash power before the actual exposure. The camera's computer evaluates the pre-flash using complex algorithms.

Traditional automatic flash utilizes a light sensor on the flash unit that measures light in real time and quenches the flash when sufficient exposure has been obtained. Generally you need to set the camera's exposure settings to match the flash, except with the 580EX II and newer camera bodies, the flash unit automatically adjusts for the camera's exposure settings.

For much more detailed information, click the link in my sig for The EOS Flash Bible.

[Curtis N]

There is no difference if using a Canon camera and a Canon flash of recent vintage.Incorrect. There are many differences.

[40Dude6aedyk]

LOL! OP didn't ask about "traditional automatic" mode. Nor did they ask about "Auto External Metering". I suppose that next you will be telling us is that there is a difference between E-TTL II and E-TTL II modes. :)

[Curtis N]

Perhaps the OP can clarify his question.

[CliveyBoy]

I suppose that next you will be telling us is that there is a difference between E-TTL II and E-TTL II modes. :)
Well, from the latest Radiopopper tech note, it seems that there is! And it affects reliability and channel efficiency. It seems that one of the problems is varying implementations of the command transmissions.

http://radiopopper.com/blog/?p=64

[Wilt]

There is no difference if using a Canon camera and a Canon flash of recent vintage.

In theory there may be no difference, but in reality there can be a ton of difference!

For example, ETTL with FEC = 0 is likely to underexpose with many Canon bodies and different brands of ETTL-compatible flashes; but if you use Metz flash in Auto, the exposure can be perfect.

Similarly, Canon ETTL wil underexpose with FEC=0 but Auto mode will also underexpose when the flash is the Canon 580EXII, and underexpose worse than ETTL mode would!

[40Dude6aedyk]

Wow, that explanation also can be used to explain the difference between Newtonian physics and Einsteinian or quantum physics. I like it.

[Titus213]

I guess it's a matter of age (the photographer, not the flash). Automatic to me is the thyristor 'auto' mode like that on my Sunpak 555. I set the ISO and f-stop on the flash and match the camera. The flash takes care of the exposure via an on-board sensor. This mode is available on the new 580EX II as I understand it.

ETTL is Evaluative Thru The Lens. The camera and flash work on concert with one another controlling the amount of light they 'think' the image needs for proper exposure based on the settings on the camera.

[PacAce]

In theory there may be no difference, but in reality there can be a ton of difference!

For example, ETTL with FEC = 0 is likely to underexpose with many Canon bodies and different brands of ETTL-compatible flashes; but if you use Metz flash in Auto, the exposure can be perfect.

Similarly, Canon ETTL wil underexpose with FEC=0 but Auto mode will also underexpose when the flash is the Canon 580EXII, and underexpose worse than ETTL mode would!
I'm going to be bold here and say that what is "perfect exposure" is a matter of personal preference. To my eyes, almost all pictures shot with a flash in auto mode, including that with a Metz flash is a tad too bright for my taste. When I take flash pictures, I usually do not want the picture to look like it was shot outside in broad daylight.

The reason the Metz flashes and a lot of others are very bright in auto mode is because the flash assumes the subject reflectance factor is 25% (this info can be found in most, if not all, Metz manuals) rather than the "normal" 18% or 13% that we think of.

However, when it comes to a choice between the results shot in auto mode between a Metz flash and the Canon 580EX II, then I'll take the Metz anytime. I have absolutely no clue what criteria Canon used to arrive at the exposure obtained with the 580EX II external metering mode. :confused:

[Jim M]

I was under the impression that Canon refers to their through the lens exposure system as E-TTL and their external sensor exposure system as "automatic."

[Wilt]

I'm going to be bold here and say that what is "perfect exposure" is a matter of personal preference. To my eyes, almost all pictures shot with a flash in auto mode, including that with a Metz flash is a tad too bright for my taste. When I take flash pictures, I usually do not want the picture to look like it was shot outside in broad daylight.

The reason the Metz flashes and a lot of others are very bright in auto mode is because the flash assumes the subject reflectance factor is 25% (this info can be found in most, if not all, Metz manuals) rather than the "normal" 18% or 13% that we think of.

However, when it comes to a choice between the results shot in auto mode between a Metz flash and the Canon 580EX II, then I'll take the Metz anytime. I have absolutely no clue what criteria Canon used to arrive at the exposure obtained with the 580EX II external metering mode. :confused:

Leo,
I use as the baseline of exposure the brightness of overall scene that would be achieved if you mounted the camera on a tripod and just let P or Av or Tv mode take care of things, using no flash at all. I believe that others, like Curtis, have similar criteria. I don't own a 580EX, so I have to take CurtisN word for it how badly Auto mode using the 580EX exposes. I know that I like the exposure offered by Metz Auto.

[PacAce]

I was under the impression that Canon refers to their through the lens exposure system as E-TTL and their external sensor exposure system as "automatic."

Canon refers to their external sensor exposure as external metering mode.

[PacAce]

Leo,
I use as the baseline of exposure the brightness of overall scene that would be achieved if you mounted the camera on a tripod and just let P or Av or Tv mode take care of things, using no flash at all. I believe that others, like Curtis, have similar criteria. I don't own a 580EX, so I have to take CurtisN word for it how badly Auto mode using the 580EX exposes. I know that I like the exposure offered by Metz Auto.

The 580EX II underexposes a lot in external metering mode. For my taste, it's under by about a stop and a third so it's probably almost two stops under for you.

[joey1234]

im wondering on a metz 58 af-1 it has auto mode, ttl and e-ttl...

[PacAce]

im wondering on a metz 58 af-1 it has auto mode, ttl and e-ttl...

If that's a question, then yes, the 58 AF-1 has auto mode, E-TTL mode and manual mode. Although the manual says that the flash also supports TTL mode, I could not get TTL mode to show up as an option even on my film camera which supports TTL.

[Curtis N]

im wondering on a metz 58 af-1 it has auto mode, ttl and e-ttl...Auto mode is as I described in post #4. With the Metz 58 AF-1 it's "dedicated", meaning that it automatically adjusts for the camera's exposure settings. Some people prefer it to E-TTL. It simply measures light within a predetermined coverage angle.

E-TTL is a bit more complex and can be used in Evaluative or Average mode, or with Flash Exposure Lock. It utilizes a pre-flash which sometimes makes people blink just as the shot is being taken.

I tend to favor Evaluative E-TTL for outdoor use. Indoors I can use any of the various options, depending on the situation.

[40Dude6aedyk]

Auto mode is as I described in post #4. With the Metz 58 AF-1 it's "dedicated", meaning that it automatically adjusts for the camera's exposure settings. Some people prefer it to E-TTL. ....
Yep, I am wrong and Curtis N et al are right about this "auto" mode. BTW, the Canon 508EXII has this auto mode "auto external metering" and so does the Sigma EF-530 DG Super (Sigma has 10 other modes as well).

But if you have a Canon camera with eTTL, I am not sure why you would want/need this kind of auto mode. It's just another complication in your life with no real added benefits. However, if you have an old camera without TTL, then maybe this mode is worthwhile to you.

[PacAce]

Yep, I am wrong and Curtis N et al are right about this "auto" mode. BTW, the Canon 508EXII has this auto mode "auto external metering" and so does the Sigma EF-530 DG Super (Sigma has 10 other modes as well).

But if you have a Canon camera with eTTL, I am not sure why you would want/need this kind of auto mode. It's just another complication in your life with no real added benefits. However, if you have an old camera without TTL, then maybe this mode is worthwhile to you.
The Sigma EF 530 DG Super has a self-contained "auto" mode feature like the 580EX II and the Metz 58 AF-1C? I can't seem to find any literature from Sigma that mentions this feature so they must not think much of it to bother mentioning it in their marketing material, huh? :confused: :|

[40Dude6aedyk]

Maybe I got that wrong too. I blame the eggnog.

[Curtis N]

But if you have a Canon camera with eTTL, I am not sure why you would want/need this kind of auto mode. It's just another complication in your life with no real added benefits.Eliminating the pre-flash has at least two potential benefits:
1) It reduces the blinking problem with the E-TTL pre-flash in dark environments.
2) It allows the use of optical slaves.
I have used traditional automatic (external metering) mode for both reasons.

[BestVisuals]

I'll give you a tip worth THOUSANDS of $$$.

The typical Canon ETTL II flash algorithm underexposes rougly 75% of all flash pictures by at least 1.5 to 2 stops. This statistic came from my extensive use of a Canon 20D and the 580EX flash.

I switched to AVERAGE ETTL metering and immediately got 95% dead-on flash exposures. Using an "EX II" flash or newer Canon camera (I now have the 5D Mk II) makes no difference, it's Canon's "Evaluative" algorithm that sucks.

When I'm outside (i.e., using flash as fill), the default "Evaluative" algorithm is preferred and does an outstanding job.

When I'm inside, where flash is 100% of the main light source, use the AVERAGE algorithm to achieve flash exposures that you should've gotten out-of-the-box with your Canon.

Flash exposure is the one achilles heel of the Canon line, IMHO.