balancing flash with ambient light

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gpc1

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Hi all,

i was taking some pics of my cousins wedding friday and was trying to balance the flash with the ambient ligtht...do you think i could get it right....nahh.

Ended up with horrible bright photos. The hall was fairly low lit and even with ISO way up i still couldnt get the balance.

Am i missing something. Do i need to set the camera to accept ettl. Does the 50mm 1.8 fo ettl. I thought that the ettl function was meant to allow the the meterig through the lens and then the flash adjusts to get the right exposure. I was shooting in manual and AV and used centre weighted metering still it just a bright picture.

50mm 1.8
Canon 40D
430ex

Anyone tried this combo in low light, if so , how did you find it and how did it work for you.


Gpc
 
You need to think of two exposures. First imagine you don't have a flash and meter the scene as normal but meter for the part of the ambient you want correctly exposed. This might mean light in the background is correctly exposed but the subject would be under.

The second exposure is the flash via ETTL. This will expose for the closest thing the light from the flash hits and bounces back to the camera. You can control how bright this is through FEC, depending on the situation you might want it at 0 or add some for bounced flash or even knock it back a bit if the subject is quite dark. Watch out for things like white tablecloths, glasses, trophies, etc. anything really bright or shiny can really play havoc with ETTL metering.
 
I can't stand ETTL flash metering. It always seems to be wrong and frankly I don't really ever feel like I understand what it's doing.

I find that keeping the whole setup on manual is actually far far easier and quicker to get the result you want. Basically set the aperture to give you the right amount of flash for your shot and then adjust the shutter to balance the ambient however you want it.

If I ever move away from full manual for flash then I would put the camera on "p" and the flash on auto and leave them to it. Any combo of part auto seems to end up in an argument between me and the camera.

It's a classic case of two chiefs is one too many. :)
 
If you're shooting direct then it can vary wildly but bounced tends to be pretty consistent as the return angles are coming from a much greater spread. With direct if the first thing returning light is very bright or dark it throws the whole thing off.
 
Thanks all,

I was bouncing the flash although the ceilings were extremely high.

I waa after the groom doing his speach. he was stood in front of a deep red velevt curtain with soft amber lighting.

I had the flash exposure reduces on the flash unit, not the camera, perhaps that wa my dowbnfall.

i think i need a tutorial on this. I really wanted to capture the room light, with just a little fill flash to bring out the groom. Instaed it was either way to dark or horribkly bright on the face.


also, that strobist site.....wow.....its pretty tricky to understand. Anyone got anything simpler with perhaps a few examle shote etc.

Gpc
 
High contast lighting situations are always the most difficult to expose for(as you found out) My advice would be to decide what is the most important part of the image(i would imagine the bride and groom etc. You can not afford to expose them incorrectly. When I used to shoot on film I had no way of checking my exposures until the negs were deved. Now I do a test shot set on manual. Decide which Aperture and ISO you'll need and move the shutter speed until the exposure is correct. Obviously make sure that your shutter speed syncs with your camera. You can use slower shutter speeds than this setting and the flash should freeze the motion on a fairly static subject. If its overexposed make your shutter speed faster until it's correct. If you need to use ISO 100 or even less. If it's still over exposed manually change the settings on your flash so you're barely using it at all. Let me know if it works. Do you shoot in raw format?Sarah K x
 
gpc1 said:
i think i need a tutorial on this. I really wanted to capture the room light, with just a little fill flash to bring out the groom. Instaed it was either way to dark or horribkly bright on the face.
Click to expand...

What mode did you have the camera in? P Av Tv M ???
 
not sure what setting i had it on, possibly manual.

i cant seem to get my head around how you balance the 2.

am i right in thinking that you meter in camera for the room light.

Eg im sitting here now and metering for low light subject, with a yellowy backlight. Looking through the viewfinder you can see that there are strong shadows on the face. It says that overall 1/60th f2 exposes slightly under. I can raise the iso but ill still have strong face shaddow. To fill those shadows with a little fill flash i would leave the camera settings as is to capture the room light and then bounce the fill flash, perhaps dialing down 3 stops in the flash unit so as not to wash out the picture.

Im keen to lear this as i have a mates wedding coming up on a beach and really need to crack this fill flash and balancing it with ambient light.

Thnks
Gpc
 
Pretty much but you don't need to dial the flash down anywhere near as much.

ETTL flash works by first firing a low power burst and measuring how much light comes back into the lens. This reading is used to determine how much power is needed for the real burst which is fired a fraction of a second later. Normally the two bursts look like a single flash as it happens so quickly. The flash is only ever powerful enough to get the right amount back into the lens. If there is ambient light in the scene the flash will fire a lower burst.

The easiest way is to just try it. Put the camera in manual, meter for the ambient light and then take a shot with the flash set to 0 FEC. Now you might need to tweak the FEC a bit depending on the scene, if there's a bright object (white shirt, tablecloth, etc) near the camera the flash burst will be lower so you'll need more FEC. If it's a dark object (dark suit, black dress, etc) then you might need to lower the FEC - the flash is always trying to get the 18% average returned so you need to compensate for scenes that aren't average.

Fill flash seems like a dark art but it's really very simple. Meter for the ambient light and let the flash do the rest, it just works.
 
Personally I have had little problems with fill flash but on a nikon its ittl.

Wouldn't bother with ambient light if the room is pretty dark anyway-would use full flash ttl and bounce off ceiling and in this case would actually dial flash up as it has further to travel than the distance the meter is going to be saying-at least 1 stop over if not 2.

Outside use direct flash i or ettl and dial flash down 1-2 stops. Remembering if the day is pretty bright but still need some fill the shutter speed may be well past your flash sync speed and in nikon case can use fast sync mode and it will ambient with any speed.
 
Thanks all,

Im of on a days landscape course on sunday with an award winning pro. so will try and put it to the test then and see the results and run through it with him.

I think for the wedding the best bet is to take quite a few shots in similar lighting etc the day before and see what needs to be done. The lighting will be consistant from one day to the next ie blue sky, nice sunsets etc. The variables will be where they stand, ie shadows, back to the sun, facing the sun etc. If I test each scenario before hand (do a dummy run!) hoefully i will be bale to better guess what is required....practice...practice...practice...

Im using a 40D and a 430ex, BTW

Rgds
 
Check out this for loads of info!
 
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