FINALLY got an E-TTL capable flash... and guess what? Now I'm confused. Surprise.

[e.rose]

I've been Googling and confusing myself further and I just need a few questions answered and I think it'll become clear to me.

This whole time I've been using a flash that only works in manual with my camera. So I understand how flash works... manually... so I *should* be good with E-TTL right? Because I did it the hard way first?

Well this is why I drive people crazy, because I over-think the "easy" stuff. :roll:

First of all... WHAT is my camera metering when that flash is attached and on? It is still only metering available light? Or is it taking flash into account? Playing around earlier today it would *SEEM* to me that it's only metering available light...

So then... if I meter a scene for the proper exposure, and then I take the shot with a flash controlled by ETTL... how does the image *not* get overexposed by the flash if the scene was already properly exposed?

On the other hand, if I wanted to darken the background... but use the flash to keep the subject bright... how the hell does one go about doing that? It seems like all the things I was doing with compensation and what not weren't yielding the desired results. The scene was either properly exposed in the end... or just totally underexposed in general.

This is easier for me to get when it's in manual, for some reason, but the issue is, I bought the flash *because* it has ETTL for the times when running a flash in manual would slow me down.

Confussled! Any wise words? Article recommendations that speak clearly and in English? Everything I keep finding seems sooooooo technically involved... and I just need some basic questions answered and I can go from there!

 

[Kerbouchard]

Well, first things, your camera meter is only metering available light. So, use that meter, and those settings to control your background and how much influence you want ambient to have on your shot.

For the flash, you should have a setting on the actual flash that is negative or positive exposure compensation. When you take a shot, the flash will fire a pre-flash, read the light coming back through the lens(ttl), and then open the shutter and fire the actual flash. It works similar to regular exposure compensation, but some things are a bit different...For instance, if you are pointing the flash directly at your subject, you will generally want to be at about -2(or more) exposure compensation.

You'll get the hang of it. Just remember that your flash output is going to change every single shot based on the conditions of the scene, color of your subject, distance the flash has to travel, etc.

As far as further resources, check out the list of articles on the right column of this site. http://neilvn.com/tangents/flash-photography-techniques/

 

[KmH]

No, you did it the easy way first.

E-TTIL is 5 times more complex, and less consistant than just doing manual flash, because you've now added a camera and some electronics instead of your eye, and programming some committe of Japanese camera software engineers wrote that is chock full of guesses about WTF it is you're trying to accomplish while making a strobed light image of something they knew nothing about when they wrote the programs.

 

[katerolla]

I too only use my flash in manual for the same reasons you do, I have watched a few youtubes on flashs and am non the wiser.
I come to the conclusion that auto if for biginners.

 

[e.rose]

No, you did it the easy way first.

E-TTIL is 5 times more complex, and less consistant than just doing manual flash, because you've now added a camera and and some electronics instead of your eye, and programming some committe of Japanese camera software engineers wrote that is chock full of guesses about WTF it is you're trying to accomplish while making a strobed light image of something they knew nothing about when they wrote the programs.

Then why the hell was everyone and their mother giving me a hard time about going with a *non* ETTL flash first?

I got *SO MUCH SH*T* for that.

And now I have one and I'm ... practically upside down trying to figure this thing out.

 

[Derrel]

No, you did it the easy way first.

E-TTIL is 5 times more complex, and less consistant than just doing manual flash, because you've now added a camera and and some electronics instead of your eye, and programming some committe of Japanese camera software engineers wrote that is chock full of guesses about WTF it is you're trying to accomplish while making a strobed light image of something they knew nothing about when they wrote the programs.

Your 550D aka T2i aka Kiss Whatever Canon camera is one of the first Canon's that is no longer a part of Canon's "colorblind system"...the original E-TTL control protocol was a DISASTER for Canon users...the E-TTL Mark II control protocol is better, but when the light meter of the camera can only meter REFLECTIVITY, and is 100% COLOR-BLIND, E-TTL II flash exposure means the right exposure, shot after shot, and then the Totally WRONG exposure more often than most people are comfortable with. As Keith said above, "chock full of guesses about WTF it is you're trying to accomplish while making a strobed light image of something they knew nothing about when they wrote the programs."

The EOS 550D aka T2i aka Kiss whatever is using a very new, basically Generation One reflectivity/color-aware metering system. It's imitating Nikon's color-aware system, but the vast majority of Canon users are not going to be able to tell you exactly how good or bad this brand-new flash metering system actually is because it is in only the VERY-newest few cameras Canon has released. The best thing to do is to read the manual for the camera, and the flash unit, MULTIPLE times, so that you are fully aware of exactly how your camera and flash set-up functions. For example: many flash systems are tied, at one level or another, to the active AF point in use, and so, when the focusing point is one,single point, the flash can be "keyed into" that active AF point. TTL flash was developed for over 20 years, based on FILM's reflectivity characteristics; digital sensors are much,much "shinier", and as a result, ALL OF THE camera, and flash manufacturers, have had one heck of a time getting TTL flash to function as well and as consistently as they were able to deliver when film was the medium the pre-flash and actual flash was being read from. Flash control )both metering and remote/multiple/triggering) is one of Canons weakest points in its entire system. Sorry, but even SYl Arena says that...he wishes most of Canon;s system was "more like Nikon's". But anyway...the thing is e.rose--you have a "new" system. Vastly different from the majority of other Canons.

You need to rrrrreally pay attention to how YOUR NEW COLOR-AWARE camera interacts with your specific flash; do you have a Canon 580 EX-II? Or a 430 EX-II? Or a Metz? Or what? You need to specify exactly WHICH flash you have when there's a flash issue. The 580 and the 580 EX-II use two different flash control protocols. If you have an aftermarket TTL flash, it might very well NOT BE COLOR-AWARE, and so its performance might be substandard with your new 550D camera. Also, third party flash manufacturers are NOT privvy to Canon's intelletual prioperty, and must reverse-engineer their flashes with their best guesses, not cold,hard data that Canon has.

Frankly, since Canon has introduced a few color-aware cameras, they are probably going to, soon, do what Nikon did, and introduce color-aware flash metering in a new series of one,two,or three flash units that can, finally, take into account the measured coloration of objects, and not just the basic 18% reflectance value that the meter wishes to turn everything into...I was there for the very FIRST generation of TTL flashes...and I am still here as i-TTL and E-TTL-II have been introduced. You asked, "WHAT is my camera metering when the flash is attached and on?" Well, the answer is, "it depends". it depends in huge part exactly WHAT flash you have, and what camera you have. SInce we do not know what flash you actually bought, it's hard to say with any certainty what it is metering. Perhaps it is thinking like a dumb, color-blind camera/flash combination; it also might depend on the metering pattern you have selected; it might also depend on the shutter speed; it might also depend on what flash "mode" you are in...TTL flash have never, ever been as simple as AUTO flash or Manual flash. Ever. Not in 1980. Not in 1990. Not in 2000. And not in 2011.

Through the lens flash metering is complex and sophisticated. Currently, Canon is premiering a brand-new metering approach to TTL Flash, one Nikon has been using since the mid-1990's; if you want to learn more about how the flash works, the best suggestion is to turn to the acknowledged masters, such as Syl Arena and his Canon flash blog, or to buy one of the books written specifically about Canon flash operation. There is far,far too much nuance to deal with in anything less than a daily blog or a book. Reading the manual for both the camera you happen to own, and the flash manual, is the best way to get accurate, correct information,. Then you need to test and re-test and keep notes on how YOU OWN gear works. The typical camera manufacturer tends to "tweak' flash performance/flash exposure/ finished photo looks a little bit, according to the "class" of camera, as well as the specific metering system. Some of the "amateur cameras" like the Nikon D80, and perhaps the Canon 550D aka T2i aka Kiss, "might" be geared toward hotter, more-fill-in flash, and punchier color than say a camera designed to be shot RAW by a slow,careful,advanced worker shooting a 5D-Mark II.

Here is Syl's blog: PixSylated - Honestly Biased Insights on Photography by Syl Arena

 

[Destin]

I've never had any issues with i-ttl. I'm using nikon, who is known to have much better flash systems than canon, but I can't imagine the canon is that much worse.

Is your flash an actual canon flash, or a third party? I'm just trying to figure out of something weird is happening with your equipment.

To get used to it at first, shoot in a semi auto mode (av or tv). To control your exposure, you have your exposure comp. Settings. The exp. Comp. On your camera body is a GLOBAL adjustment. Meaning it affects both ambient and flash exposure. The exposure comp. On your flash is a local adjustment that controls flash output, and not ambient exposure.

What's this mean? Well, say you want to darken the background and keep your subject properly exposed: you would dial down the in camera ev adjustment until your background is where you want it. Then, you would increase your flash ev to bring the exposure on your subject back up to where you want it.

It's pretty simple once you get used to it. Your a smart cookie, I know you'll get the hang of it.

I highly recommend the book "the hot shoe diaries" by joe McNally. He shoots nikon, but much of it still applies to canon as well.

 

[e.rose]

@Derrel - Holy cow. Definitely gonna have to read that again in the morning when my brain is fresher, because I'm pretty sure I only soaked in about %5 of that information. Thanks for taking the time to write it out...

@Destin - It's a Canon 430EXII. I started out playing around in Av mode... but the issue with that was that my shutter speed was making slight changes between shot to shot... so to be consistent I switched back to M mode.

I actually have Hot Shoe Diaries. I've had it for a couple of months now... and it's helped with OCF aspects, but it doesn't really offer any ... dare I say... "real" information on trying to figure out ETTL.

It's more of a leisure book for me than a strict learning tool. It's cool to see how he does what he does, but again, I got more out of it for OCF purposes than I ever did for on camera flash.

Maybe I just don't remember those parts though, because I'm definitely taking my time getting through it, haha.

 

[Big Mike]

I use E-TTL all the time.

I keep the camera in manual mode. I set the aperture for the DOF that I want, keeping in mind that the smaller the aperture I choose, the harder the flash has to work (and will eventually reach it's limit). I set the ISO for the ambient exposure that I want/need, keeping in mind that a lower ISO makes the flash work harder. For a wedding reception, I usually don't go lower than 400, so that the flash can recycle quickly.
The flash (in E-TTL) will match it's power to the aperture and ISO that you have set. It uses a preflash, so just like the auto modes, the exposure will be dependent on the reflectivity / brightness of what's in front of you. You can use FEC to adjust the flash exposure away from it's metered value.

The cool part is that you can use the shutter speed to adjust the ambient exposure, but with no affect to the flash exposure (just don't go over the max sync speed). So if you want more background exposure, you use a slow shutter speed (dragging the shutter)...if you want less background (ambient) exposure, then you can use a faster shutter speed. And of course, aperture & ISO still have the expected affect on the ambient exposure.

Of course, if you use too slow of a shutter speed, the ambient light may give you some motion blur...but the flash can also freeze motion. You can even get both in one shot and have motion trails. But if you try this, make sure to set the flash to 2nd/rear curtain sync. (I think that's a custom function on the camera).