# How to shoot group indoors with flash



## sfogel2 (Oct 23, 2011)

Hi, all...

I would like some advice, please, on how to balance all the tradeoffs when shooting a group indoors.

*The scene*: 8 high school girls dressed up for homecoming dance.
*The victim*: Dad, trying to get the best indoor shots of the group
*The equipment*: Canon EOS Rebel T2i, 18-135mm f/3.5-5.6 USM IS lens, Speedlite 580EXII with diffuser
*The settings*: Av mode, f/11, ISO 400, 1/60sec (Custom flash setting for Av = 1/60 to 1/200
I wasn't that happy with the results. Everyone was in focus, but exposure was just OK and needed tweaking on computer. Sometimes not enough detail in shadows, like a black dress. (Couldn't move group and they were in a narrow alcove with glossy white paint on walls and ceilings.)

How do you balance these tradeoffs?

Shutter speed needs to be faster than 1/30 to avoid camera shake
ISO must be kept low to avoid noise
Aperture must be f/8 or narrower to keep everyone in focus
Want as much ambient light as possible to avoid glare
That last one is a new revelation of mine. I believe that when shooting in Av, the T2i tries to meter for the background. So maybe adjusting so more ambient light can get in would be a good idea. Maybe because I have an IS lens I could go to 1/30.

Any advice would be welcome.

Steve


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## Derrel (Oct 23, 2011)

ISO must be kept low to avoid noise.

Errrrrrr! Buzzer!!!!!!!!!!!!!!! Noise? You have a Canon T2i...you can go to ISO 400 or 500 or 640, and not have a noisy image. Go to ISO 800, and ditch the diffuser--all it is doing is costing you output.

You are making the classic beginner's error, that of worrying about ISO speed and theoretical noise...modern d-slr cameras are not objectionably noisy at ISO 640, or even 800, especially when the exposure is "adequate" to generous.


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## MLeeK (Oct 23, 2011)

sfogel2 said:


> Hi, all...
> 
> I would like some advice, please, on how to balance all the tradeoffs when shooting a group indoors.
> 
> ...



I have a tutorial link somewhere on metering and exposure I'll see if I can find and send to you.


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## sfogel2 (Oct 24, 2011)

Hi...thx for the info (and the tongue lashing . I did bounce the flas, BTW.  Now I see I should have used center weighted average metering to avoid having those bright white walls reduce the exposure. Great lesson on ISO. You are right. Shadows were underexposed and had to raise them in software, and that added noise. One question...in a flash situation is it sometimes smart to set exposure as if you weren't going to use flash and then add the flash for a better exposure of your subject?


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## MTVision (Oct 24, 2011)

I'm not to great with flash but I don't think it would be a great idea to expose as if you weren't using a flash. For one the whole exposure triangle is a little different with flash. Aperture controls only the area affected by the flash whereas shutter speed controls the area not lit by flash (background). So, basically a slow shutter speed will show the background more and a fast shutter speed will darken the background.  

The below tutorial explains about off camera flash but I don't think it would be any different then having a flash mounted on the camera. 

Anyways, check out the tutorial below. I cut parts of it out because it was really long and it explained about how to set up an off camera flash shot. 

-Andrea Joki wrote the Tutorial that the below information came from-

You'll probably want to use your speedlights manually to get an understanding of how to set up a flashed shot.  Also, using manual gives you the opportunity to be consistent with exposure across whole sequences. So I've structured this with manual (not TTL) in mind.

First, exposing with a flash is a bit different than exposing for natural light.  With normal exposure, you know there is a relationship between aperture, shutterspeed, and ISO and you make constant compromises in each of those for the best exposure.  With flashed images, you don't have those compromises!  Flashed exposing is actually much easier.   If you remember that aperture controls intensity and shutter controls duration, then you realize how easy it is!

Aperture choice ONLY affects the area that gets lit by your flash.  ONLY!
Shutter choice ONLY affects the area that is not lit by the flash (background).

Aperture controls the exposure of the flashed area of your image and shutter controls the background that isn't lit by flash.  How easy is that?  Shutter has NO relationship whatsoever with the flashed portion of your image.  Why - because aperture controls light intensity - when you take a picture, the camera's aperture opens up and the area that was flashed is immediately exposed - and then the background will start to expose based on the amount of time you told the shutter to stay open.  But the area exposed by the aperture won't expose more because of the open shutter.

If you keep the two rules in mind - aperture controls flashed area and shutter controls background, you get an idea of how to set up exposure for an OCF shot.  

Now, there is much more to this, of course - the power of your flash output, the brightness outdoors, how diffused (modified) your light source is.  But at its basic level, here's how to set up a shot with a flash:

Make sure your shutter speed is at or below your camera's synch speed.  For most cameras, that is SS250 or less.  For 5Ds, that is 200 and for the D70, synch speed is 500, I believe.

Set your aperture at about F/4 and take a test shot with the flash triggering.  Ignore the background (whether blown or dark) and look only at your subject.  Is he too bright? Make your aperture number bigger (close down).  Is he too dark?  Make your aperture wider.   The pros usually only need one test shot and a look at the histogram to determine what aperture.  This works whether you have the flash pointed at the subject or bounced/diffused. Just make sure not to move the subject or flash after that test shot since you need to make sure the distance between the flash and subject remains the same (or your exposure will change and be wrong!).

Once you have your aperture, then you can decide if you want the background (a nice sunset perhaps?) to show or if you want the background dark (remove clutter?).

A consideration is how bright it is outside.  You may have to adjust ISO or change the flash output in order to get an exposure at the shutter synch speed.


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## MLeeK (Oct 24, 2011)

sfogel2 said:


> Hi...thx for the info (and the tongue lashing . I did bounce the flas, BTW.  Now I see I should have used center weighted average metering to avoid having those bright white walls reduce the exposure. Great lesson on ISO. You are right. Shadows were underexposed and had to raise them in software, and that added noise. One question...in a flash situation is it sometimes smart to set exposure as if you weren't going to use flash and then add the flash for a better exposure of your subject?


It can work, but you have to kind of have an idea of what you are doing too. If I want to use a speedlight as a little bit of fill in e-ttl mode I have often setup my exposure as proper on the subjects and then dropped it down a bit to let the flash fill in and keep the background in line with the exposure, but it's not really a sure fired way to get what you want. 
Strobist is a WEALTH of information on using flash. About 1/2 way down on the right side you'll see the drop downs. Start with the lighting 101 archive drop down and read through all of the stuff he has there at your leisure. You'll learn more from that free website than you can imagine.


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