Balancing ambient with speedlight question.

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Hi Guys

I'm interested in getting better fashion like images outdoors and I really like the way pro's lower the ambient by maybe 2 stops and then use the flash to really make the model ping.

Well I went out and tried the balancing ambient and flash thing. I read that you meter for the ambient first with flash off (say 250/1 at f5.6). Then you need to meter the flash so that it puts out f5.6 of light from wherever I have the flash right?

So with the ambient matching the flash - I am free to shoot yes?

If that is correct then i've got that bit but what happens if the sky meters over my highest setting on the flash (which is 1/250sec)......say 1/500 or even higher on a real sunny day 1/2000.

I did (I think) switch to high speed sync but this is where I lost any desirable look to the image and I believe the model started to lose the light on her face along with the background becoming murky.

So if I go over this 1/250 setting on the flash, does that mean the flash output is affected? why please?

I know shutter controls ambient and aperture controls flash but I have no idea how to balance the 2 when you are shooting into a bright sunshine at midday (as an over the top example because I would try to avoid that time of day altogether).

If the shutter reads 1/4000 into the sun behind my model - how do I get the flash to balance the light onto her face?

Is it best to always try and shoot in ambient light that falls into my 1/250sec maximum limit on my speedlight?

I hope somebody can help as I am starting to love what I can achieve here.

This image was a test shot for balancing flash and ambient at 12.30pm which is not ideal time to shoot.
I used 2 flashes through white umbrellas at f5.6 on each side. The ambient was 1/250sec. I don't think its too bad but like I say, If the background had been brighter - I would't know how to bring the ambient down and keep the model evenly lit.

P.S - I wasn't looking to frame or get any type of desirable pose going here - just lighting for now.

Any response is much appreciated
Thanks for reading guys

Chris.



IMG_4716 by Chrisly2011, on Flickr
 
I'm starting out myself, so this may a load of hot-air.

Aperture also controls ambient light, so for getting your ambient, I'd have no problems setting a smaller aperture to get the shutter speed within my flash sync speed.

The flash is different, the actual duration of the flash is very short, and is a fixed duration, not matter what the shutter speed.. Hence for flash, the rule of thumb is within normal sync speeds, aperture only has an effect..

So, for your situation, meter the ambient to be within flash sync, adjusting shutter/aperture as desired.. Then whatever aperture you end up with, use that as the basis of setting your flash (adjusted according to your desired ratio).

I think that's the theory, I'm happy to be corrected, I need to learn from my mistakes too!


[edit] Here's a good tutorial, http://www.sekonic.com/Whatisyoursp...icles/Balancing-Flash-with-Ambient-Light.aspx

This is the paragraph I've tried to explain..
So, now the light on the model was the same as on the background. However, I wanted the background to be more muted than the foreground, so I used a shutter speed of 1/125 second for the picture. This underexposed the background by one f-stop, which is what you see here, but the exposure on the model remained correct. Why? The reason is that the meter reading for the background was for the ambient light. The flash was too far away to affect the rear portion of the cavernous room, and therefore the exposure for the background was entirely dependent on the f-stop / shutter speed combination.

For the exposure of the foreground, though, the lighting came from the flash only. Therefore, changing the shutter speed didn’t affect the exposure of the subject, since the speed of light is faster than any shutter speed. It was only the amount of light let into the lens through the aperture that determined the exposure.
Click to expand...
 
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One way to do it would be set camera on manual and get a good exposure without flash. To get a good exposure with decent shutter speed without flash. I.E. ISo 400, F2.8, 1/60.

Make sure your shutter speed does not exceed your flash sync speed or drop lower than the focal length of your lens.

Then add flash using manual flash mode starting at 1/4 and work your way up or down until you get the visual look that makes you happy.

Flash meter only gets you in the ball park anyway, ultimately you are going to fine tune your flash by looking at the LCD on your camea or Histogram. This is the beauty of having a Digital camera with and LCD.
 
'Balancing' is one thing, but generally the results are better if we can overpower the sun by a stop, or maybe two - and that just isn't possible using speedlights.

The only way or doing it, other than using either a powerful location flash system of several speedlights cobbled together, is to shoot in poor light.
 
As noted above with speedlights it's tough

Regards the exposure, if you find that your ambient is (as you say) 1/250th, ISO100 and f5.6, just switching the aperture alone to f8 would have darkened the background but would require one stop more flash power (if available).

Once you start getting very bright conditions then as Garry says, it's impossible to over power the sun with a single speedlight. Even expensive units like the Elinchrom Quadra's will struggle to over power the sun in the fullness of mid day.

You can add your second speedlight to the mix - so 2 firing into the same brolly (single light source) that would give you an extra stop of light then you need a further 2 to get another stop and the another 4 for the third stop - So it can be very expensive.

Remember that although shutter speed controls the ambient, the ambient exposure is also affected by the aperture. So to slow the shutter and darken the background you can make the aperture smaller f8 or f11 but you will need the power of the flash.
A light meter will be a big help. The meter does not get you "in the ball park" as someone above noted, it will be precise if used correctly.

Incident ambient reading from subjects position will let you know where to be with the ambient exposure. You can choose to amend the aperture and shutter speed to suit what you want the background to look like.

Add in the flash and swich to the flash setting and the meter will provide an accurate reading - adjust power till you get the aperture you set on your camera.

I couldn't disagree more with MrG though. A light meter will provide precise readings at any position in your image. A histogram is a representation of tones.

Looking at the histogram will get you in the ball park - to be precise a meter is a big help. The screens on the camera are really not big enough to check for exposure and are not calibrated.
 
Would taking the shot in that dappled shade behind the girl have helped? natures own diffuser sort of thinking.
 
Shooting in the shade would reduce the exposure on the subject. But the OP is trying to control (and overpower) the bright ambient light so would still likely have the issue as the background may have the bright sunlight hitting it.
 
A great source for such info is the Tangents blog by Neil van Niekerk, loads of articles on balancing light such as this one but at the end of the day like others have said there's only so much juice in those units :)
 
Oooo that looks great Steve , added to faves for a reaal look later .
 
The cheapest way is to find some shade.
 
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