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12/16/2005 02:30:00 PM · #1 |
I just bought a Canon 580ex flash. Unfortunately, the manual is very UNspecific on the how's and why's of the different settings. There are several modes on the flash..."ETTL", "M", "MULTI", etc. So far, the best results that I've had are in the ETTL mode. It doesn't blowout the pictures like the M mode does. What IS ETTL (I don't think the manual even explains it!)? What does the M mode blowout (super overexpose) the shots? Is the ETTL mode more "intelligent?" Any info would be appreciated. Thanks!
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12/16/2005 02:37:51 PM · #2 |
If I understand correctly the M is for manual mode so the photographer sets the flash output manually.
ETTL is a through the lens system which sets the flash output automatically according to the fstop chosen.
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12/16/2005 02:41:41 PM · #3 |
the 20D has ETTL-II, it stands for Electronic Through the Lens Metering. It's their second generation, hence the II.
Basically the flash fires and the flash monitors the reflected light through the lens. Once it thinks there has been enough light to properly expose the film, it stops the flash.
If you set the flash on Manual, you have to select the focal length of the lens and the power and the exposure compensation. If you do it right, it should not overexpose the shot.
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12/16/2005 02:43:41 PM · #4 |
| Thanks a lot. That answers a lot of questions! For most applications then, I should probably just leave it on ETTL? |
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12/16/2005 02:46:40 PM · #5 |
E-TTL - The flash and the camera decide automatically how to set the flash output. This works surprisingly well, considering all the things that can go wrong.
Manual - The photographer sets the output as a ratio of full power ie. fullpower, 3/4, 1/2, and so on usually over a several stop range.
Multi - The flash discharges multiple times while the shutter is open, creating a stroboscopic effect.
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12/16/2005 02:50:03 PM · #6 |
Try this, perhaps it has more info....
download manual |
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12/16/2005 02:50:36 PM · #7 |
Originally posted by chafer:
Thanks a lot. That answers a lot of questions! For most applications then, I should probably just leave it on ETTL? |
Absolutely, for routine usage. A good time for manual is when you want "fill-in" flash; you can set it on a low power setting and fill up too-dark shadows without overpowering them. As, for example, doing a portrait in bright sunlight, to soften the shadow of the nose on the face...
Manual option is also needed when you use lenses that don't communicate witht he camera, if you have any of those.
Robt. |
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12/16/2005 02:58:57 PM · #8 |
//photonotes.org/articles/eos-flash/
Everything you wanted to know and MORE about using your canon flash. This is a very LONG but worthwhile read.
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12/16/2005 03:07:21 PM · #9 |
That's interesting; apparently Canon defaults to fill-flash mode when ambient light is above EV 10, and you can use flash exposure compensation to fine-tune that. I had just been doing it manually perforce of habit, but it comes easily to me so....
Great article John. Bookmarked...
Robt. |
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12/16/2005 03:30:48 PM · #10 |
Boy oh boy, the information out there, and how wrong much of it is...While i have a Metz 54 and the details may vary a bit, this is how it works:
E-TTL =(evaluative TTL) (1 or 2) the CAMERA decides the proper exposure - it turns on teh flash and will turn off the light when it figures it has received enough light. The flash does no 'thinking'.
M - the photographer decides the flash's output, and that output is constant.
Multi - like a disco stobe
P mode (i think that is it) this is high speed sync. If for some odd reason you want ot use the shutter at a faster speed than the sync (1/200 or 1/250) then you need to put the flash in this mode.
Auto mode (if the cnaon has this - the Metz does) This is where the flash does the thinking - it reads the ISO/Ap and Tv from the camera and decides on how much light is proper and shuts off when it 'seees' enough.
IF you are finding your shots w/ flash in eTTL mode too dark or light all the time, then you can adjust that via FEC - flash exposure compensation. In Auto mode the flash has it's own FEC.
The flash has auto-zoom so as you zoom your lens the flash nead internall moves. if you move it to bounce the flash then the head goes to full wide, unless you override it.
Camera and flash modes
Full auto (green box) is just that, full auto.
Aperture priority - the camera will adjust the shutter speed between 30 seconds and sync speed to expose for the ambient light. This is fill flash by default. NOTE: 30 seconds is too long to hand hold!! If the camera cannot get the proper exposure then the shutter speed display in the viewfinder will blink.
Shutter speed (Tv) - User chooses a shutter speed up to sync speed, the camer will set the aperture to expose for the ambient light. This is fill flash by default. If the camera cannot get the proper exposure, the aperture value in the viewfinder will blink.
P mode - this operated very differently with a flash attached. Yo ucan adjust aperture. Shutter speed is locked (on teh 300D at 1/200 - sync speed). In this mode the camera assumes the flash is the main light - NOT fill light ever. The background behind the subject may go dark.
If you are used to shooting without a flash and using the half pressed shutter to lock in focus and exposure, you will find eTTL frustrating. You have a seperate button to press to lock the exposure!!! This is where Auto mode on the flash is great - you use the camera just like without a flash.
Message edited by author 2005-12-16 16:34:52. |
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12/16/2005 03:41:52 PM · #11 |
Originally posted by Prof_Fate:
P mode (i think that is it) this is high speed sync. If for some odd reason you want ot use the shutter at a faster speed than the sync (1/200 or 1/250) then you need to put the flash in this mode.
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Actually, this mode is a lot more useful than it would seem. It allows fill flash when ambient light levels won't allow a shutter speed lower than the sync speed. An example would be if you wanted to shoot with fill flash and have the lens aperture wide open (or nearly so) to blur the background, but the ambient light was bright enough to require a shutter speed over the sync speed. You could stop down until the shutter speed was under the sync speed, but that would compromise the DOF you want. High Speed Sync means you do not have to make that compromise.
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