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10/26/2005 06:49:02 PM · #1 |
I have read the manual a few times and still get confused as to whether what I want out of my 420ex is possible.
I shoot 80% in Av, 10% in Manual, and 10% in everything else. There are many times when the light will support say 1/30th at f/8.0. I want to shoot two stops faster (1/125th) with the same f-stop. How do I tell my flash to provide the extra light for me? Usually on Av the flash seems to just provide "fill" as the shutter speed doesn't change with the flash on or off.
You can use P or Green, but those are limited to 1/60th and f/4.0. Does anybody understand what I'm getting at? |
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10/26/2005 07:01:39 PM · #2 |
| If you already know what stop and speed you want to shoot at, why not stay in Manual and let the flash worry about the rest? |
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10/26/2005 07:33:53 PM · #3 |
Yep thats what I do
I shoot 100% manual
I like to have the control hahaha :P
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10/26/2005 07:48:08 PM · #4 |
//photonotes.org/articles/eos-flash/
will tell you all sorts..
The important thing to know is that Canon flash system meter the flash and 'main' exposure seperately.
So... If you meter 1/60th at F/8 and you want to shoot at 1/250 F/8 just set that in manual, turn on the flash, and the flash exposure will fill the foreground to meet the correct exposure... In theory. :-).
Same in Av mode. If you use exposure comp -2 stops the flash exposure will still be correct, but the 'background' exposure give by the shutter/apeture setting will be 2 stops faster..
Cheers, Me.
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10/26/2005 07:49:45 PM · #5 |
Forgot: You can use FEC (Flash exposure compenstation) if you've got the hacked firmware, a 550ex, 580ex or different body (10D/20D/5D/1D etc), which will change the flash exposure relative to the main exposure, BTW.
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10/26/2005 10:18:44 PM · #6 |
| OK, I'll try manual. I'm certainly not scared of it, but the meter reading was making me think that I wasn't getting anything out of switching. If I switch to 1/125th (which should be 2-stops underexposed), the meter reads 2 stops underexposed and I thought the flash would "think" I wanted a dark picture. I'll goof around with it. |
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10/26/2005 10:26:47 PM · #7 |
Originally posted by KiwiChris:
Forgot: You can use FEC (Flash exposure compenstation) if you've got the hacked firmware, a 550ex, 580ex or different body (10D/20D/5D/1D etc), which will change the flash exposure relative to the main exposure, BTW. |
That was my thought. Wouldn't you be able to work with the FEC with the hack? Would that help improve what you are after? I found the not having FEC was a drawback to me with my 420ex but since installing the firmware hack I use it all the time. Though, unless I'm shooting with studio lights I normally shoot in P mode cause I'm slack! :p |
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10/26/2005 11:11:12 PM · #8 |
In Av mode the camera will meter the ambient light only. It can't calculate the flash. Your options with an external flash are manual, Shutter priority, or Program normally. Program mode is quite good with an external flash. If you want certain setting then set it in manual. Normally 1/125 sec and f5.6-8 are good. The ETTL should do the rest.
The FEC works well. Most people would recommend underexpose for digital. You then bring it back out in post processing. The results can be quite good like that.
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10/26/2005 11:42:25 PM · #9 |
This is how canon's ttl works:
In P mode the camera assumes the flash is the only light. the background may go dark. the shutter speed will lock at 1/60, so all you really can adjust is the aperture. You can load the undutchables hack and get 2 things - teh ability to lock this at 1/200th sec AND Flash Exposure Compensation (more on that later)
A and T mode - the camera is metering for the ambient light, so the flash will act as fill. BUT in A mode the shutter will be set automatically, and that can be as slow as 30 seconds. Notice not 1/30, but a full thirty seconds. In T mode since your sync speed is 1/200 there is no point to going faster, and since the flash duration will freeze motion, there is really no point to T mode with a flash.
M - now we're talking. You read the meter and set for what you want, the flash will try and put out enought light for a proper exposure. What i find works well and looks decent is to set the shutter to 1/125, and then use the Aperutre to set the exposure 2 stops under. the flash can make up the 2 stops and things look good.
In eTTL-mode the camera does the measuring and thinking. It turns the flash on and off. In all but M mode it used evaluative metering, and works reasonably well. In M mode, though, it goes to center weighted metering. You can lock the meter reading yourself if you want, recompose and shoot. What you will often find is the shot is undrexposed as the camera read the light off soemthing bright or reflective (a white wedding dress for example). This is a 'flaw' in e-TTL. e-TTL2 is supposed to be better. Exposure compensation will fix nothing. You need Flash Exposure compensation, and on teh Rebel you need to load alternative firmware (aka Hack) to get it. It works and is worth it.
I use a Metz 54. It has an excellent auto mode. To shoot this way (the flash in auto mode) the flash will read teh camera settings (iso, shutter, ap) and determine the amount of light to give off. Now you can lock exposure or shoot as if there was no flash, and things will work just fine.
FEC is also handy if you bounce your flash, or use flash modifiers (omnibounce, lightsphere, etc).
When in doubt shoot RAW - you can recover 2 stops of light that way.
Message edited by author 2005-10-26 23:42:43. |
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10/27/2005 12:26:00 AM · #10 |
Thanks guys. This is helpful. I use bounce a ton. I will switch to more M-mode when I'm doing studio stuff and not be scared of what the meter reads.
I've gone as far as downloading the hack, but haven't installed it yet. It's just waiting there for me. |
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