# On-Camera Flash: ETTL or Manual?



## snerd (Oct 8, 2013)

I've been playing all morning with my 7D, 17-55 IS and a 430EX II. When I use manual, I have to adjust power anywhere from 1/8 to 1/4 to get acceptable indoor flash shots. Using ETTL, all are much darker. So I've set the FEC up to +1 1/3 and get similar, reliable shots indoors. So, 6 of one and a half dozen of the other. I'll probably just leave it ETTL II with flash exposure correction upped when shooting on-camera. Of course, I know I'll need to go manual when I purchase a lighting kit and go OCF.  Any discussion on this?

Also, reflective or shoot-through umbrellas............ which is your favorite? Thanks!


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## amolitor (Oct 8, 2013)

That sounds wrong. Something's busted, or there's some kind of user error going on here. I'd try to figure out why the TTL ain't working right.


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## Big Mike (Oct 8, 2013)

You need to understand what E-TTL is doing.  Just like automatic exposure modes, it's designed to get exposures wrong, but in predictable ways.

E-TTL works by sending out a pre-flash, just before the shutter opens.  That light reflects off of anything in it's path, and that reflected light (the bit of it that comes back Through The Lens).  So based on how much light is reflected back, the camera and flash decide how much power the flash should output when the shutter is open.  This all happens very quickly before the shutter opens...you probably don't even realize it has fired twice.

So if your scene or subject are very reflective (bright), then lots of light will be reflected back to the camera.  The camera reads that and gives you less light from the flash...hence the under exposed photos.  This is why you need to use positive FEC.  

But on the other hand, if your scene was mostly dark (not very reflective) the flash would likely put out too much light, requiring you to need negative FEC to get a proper exposure.

On top of this, E-TTL is uses Evaluative metering...meaning that is tries to evaluate the scene and look for ques that would help it to make a 'good' decision on how much light to put out.  The result is that for the average person, taking the average photo...it usually works well.  But it can also be confused or fooled and give you unpredictable and inconsistent results.  Also, E-TTL may be a little biased toward under exposure, just because blowing out highlights is a no-no for digital photography.

So should you use E-TTL or manual?  It's up to you.  Manual mode (once you know how to use it) is very consistent, which is why a lot of people like it.  E-TTL doesn't require the knowledge or calculations that it takes to use manual, but it can be inconsistent.  There is not correct answer, just use what works best for you in your situation.  I use both.

I prefer to bounce out of an umbrella, rather than shoot through...but I'll use both.


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## table1349 (Oct 8, 2013)

Great resource when working with Canon flash:  Flash Photography with Canon EOS Cameras - Part I.


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## Derrel (Oct 8, 2013)

Some cameras seem to be overly influenced by the specific AF bracket that is active when shooting with TTL flash control. That "might" be one of the things that causes erratic flash exposures. It is a variable that you can easily test out with a few simple set-ups and a camera that's kept in the same,exact spot, while the AF spot in use is shifted.

Smaller umbrellas for speedlights: I prefer reflecting umbrellas over shoot-throughs. I started out with ALL shoot throughs, but once I bought some decent reflecting umbrellas, my entire outlook changed. Photoflex makes a decent reflecting umbrella, their "convertible" model, and I also have a set of British-made umbrellas that have a dull, pure-white, almost rubberized cloth-like lining that yield nice light from speedlights.

Photoflex's 30 inch RUT model works well with speedlights, and gives a light source that must be 500 to 800x larger than the bare fresnel lens of a 285 or 430EX flash unit used "bare". There's little need to go ga-ga by trying to use 45 and 60 inchers with a speedlight...most speedlights cannot even begin to "fill" an umbrella much larger than 32 inches.

Photoflex UMRUT30 Convertible 30in White Umbrella UMRUT30


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## Robin_Usagani (Oct 8, 2013)

I do both but 80% of the time when it is ON camera flash, I use ETTL.


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## snerd (Oct 9, 2013)

Thanks! Some good information to help me along with my lighting journey.


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## pgriz (Oct 9, 2013)

If the subject is reasonably close (5-20 ft.) and moving (think family occasions) then ETTL is usually fine.  The results are somewhat inconsistent, as Derrel has noted, but that's ok for a set of family snapshots.  If I need to have the exposure and balance of light correct AND the subject is static (product photography, portraits, interior shots, still life, etc.), then I would usually go to manual OCF.  Manual on-camera is just awkward.  However, I have been in situations where the ETTL was just too erratic, and I went to manual with the flash on camera - just had to remember the distance range at which the manual flash exposure was "correct".  The problem is, that at close range the inverse-square law of light distribution means that the acceptable range is very narrow.  So using manual flash on-camera probably works better if the subject is further away and the zone of acceptable exposure is deeper.


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## hirejn (Oct 17, 2013)

ETTL can be fooled, which leads to darker exposure. If you don't think that's the problem, there may be something not working but I've never heard of that. It would be strange for manual to work but TTL to not unless something is consistently fooling the meter. Send it in to Canon. Or look at other variables. On Nikon, the exposure compensation dial on the camera can affect flash in manual mode. Maybe something like that is happening where you forget your compensation on the camera is down.

I don't prefer umbrellas. I prefer soft boxes.


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