E-TTL vs manual flash

took these shots with a 50d sigma 18-200 plus 580ex set at fec of -1
tv mode with direct on camera flash
think they look ok what i want to know is this
since many on this board advise shooting in manual flash how do i equate an fec of -1 or 0 in ettl to a manual flash setting /
do i start at say 1/8 to 1/16 and just chimp from there or is there a specific formula

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Assuming the manual flash output does not have fraction power output (in which case you simply choose 1/2 of the current power setting), simply stop down the lens aperture by -1EV in order to do the equivalent to ETTL with FEC= -1EV

Patrick,, looking at the women's skin tones and ethnicity, your exposure is pretty good..

When I mount my flash (430EX or 430EXII ) on camera I always use ETTL which I find pretty reliable for most situations.. Tricky lighting can effect flash exposure sometimes, so I just adjust the FEC to suit..

I use manual flash when shooting off camera flash with camera in manual mode.. I use a flash meter to read the flash exposure.. You have no FEC with manual flash..

Another thing to think about is when the flash is the main light source it's always best to set your camera to manual mode for the best control..

patrick clarke wrote in post #10151468
how do i equate an fec of -1 or 0 in ettl to a manual flash setting

There is no way to equate ETTL with an FEC setting to a manual flash setting. This is because you don't know how much flash power was being used in ETTL.

Yes, you start with a educated guess at how much power you need, and then chimp the results. Keep in mind that if you change the flash to subject distance, you will need to change the flash power setting.

Yes, you read right. EVERY TIME you change your position relative to the subject, you will have to adjust your flash.
(If you want to change your aperture or ISO, you will also need to adjust your flash power)

That is why manual flash is really only good in a studio setting where nothing moves much. Out in the real world, when walking around shooting various subjects at various distances, you need ETTL.

Much like the white whale, I have heard legends of photographers that can shoot with manual flash that just know what settings to use in any given condition. Crazy, I know.

You learn that pretty quickly, if you do it a lot. When I had my first camera, manual flash was the only thing available. Not that you could change the power of it either, so you had to change the aperture.
You quickly learned which aperture to use for certain distances.

I always chimp, though I'd quite like a flash meter. I've never used E-TTL before though so I dunno what I'm missing out on.

Once you get to know your flashes, Leroy_sunset is right, you can guess and get pretty close.

thanks for all the replies
they are really helpful

e-TTL works well for most situations. You can make exposure adjustments with FEC. About the only time I use manual mode is when I want to get rid of ambient light. Then, just set your camera in manual mode at f/11, iso100, 1/200 shutter speed. This will get rid of most ambient light except outdoors, when you will probably need high-speed sync. Adjust your shutter speed from there to work the ambient, and work the flash with manual power adjustments.

leroy_sunset wrote in post #10152432
Much like the white whale, I have heard legends of photographers that can shoot with manual flash that just know what settings to use in any given condition. Crazy, I know.

This is actually very EASY!

One simply has to know the Guide Number of the flash for a given FL coverage area, then know what distances represent what zones for a given aperture.

For example, if a flash Guide Number is 120, then f/4 is at 30', f/5.6 is at 21', f/8 is at 15', f/11 is at 11'. Simple arithmetic. Since the flash is on Manual (unchanging) power output, one only has to memorize this simple series of distance and aperture.

Modern flashes complicate this with their variable zoom heads under camera body control. To make it simple once more, one merely sets the flash to Manual Zoom control, and fixes the angle of coverage to one setting.

In my teens I would shoot high school dances using fully manual flash, and I only needed remember a few distance-aperture combinations to be able to shoot all night, and to do so quite rapidly based upon visual estimate of distances (since the room was too dark to easily read the distances on the lens scale).

Automation makes things too simple, and dumbs down users unfortunately!

Wilt wrote in post #10154601
For example, if a flash Guide Number is 120, then f/4 is at 30', f/5.6 is at 21', f/8 is at 15', f/11 is at 11'. Simple arithmetic. Since the flash is on Manual (unchanging) power output, one only has to memorize this simple series of distance and aperture.

Thanks for this! Makes so much sense...I'm just geting into manual flash, and this will help loads!!

David

Wilt wrote in post #10154601
This is actually very EASY!

For example, if a flash Guide Number is 120, then f/4 is at 30', f/5.6 is at 21', f/8 is at 15', f/11 is at 11'. Simple arithmetic. Since the flash is on Manual (unchanging) power output, one only has to memorize this simple series of distance and aperture.

What's that in metric

yogestee wrote in post #10157798
What's that in metric

Guide Number 120' = Guide Number 36.6 meters. Wise-ess!

The flashes are sensible, i.e. metric, in their model designations. The 580 EX II has a guide number of 58, the 430 has 43, and so on. Meters, nothing else.

apersson850 wrote in post #10159048
The flashes are sensible, i.e. metric, in their model designations. The 580 EX II has a guide number of 58, the 430 has 43, and so on. Meters, nothing else.

Metric they are, but useless guide numbers for ordinary shooting with WA or normal lens FL, as they are valid only with zoom head at the longest (tele) FL position!