flash photography techniques
on-camera flash outdoors ~ metering techniques ~ flash exposure compensation

exposure metering techniques

Camera technique can be distilled into a few elements:
– composition & framing, including lens choice
– timing of the photograph, ie that moment
– choice of aperture (for depth of field)
– choice of shutter speed (for subject movement)
– exposure metering, (which obviously ties in with aperture & shutter speed)

That’s it! There’s not much more we can do with our cameras at the time of exposure. Ultimately so much of what we do depends on how we juggle those three settings – shutter speed, aperture and ISO.

The balance between those three camera settings is determined by how we meter for correct exposure.

This photograph was shot in Manual mode: 1/2000 @ f/1.4 @ 400 ISO
I metered specifically for the model, Anelisa, instead of allowing the much brighter background to influence my exposure settings.

This image helps explain why specifically setting the aperture and shutter speed in manual exposure mode, is different than using aperture priority (for example), and have the camera select the shutter speed for me.

 

shooting in manual exposure mode on your camera

I shoot nearly exclusively in Manual Exposure Mode, and for very specific reasons:
– I want to control the accuracy of exposures,
– I want to control the consistency of exposures,
– I want to control the depth of field,
– I want to control subject / camera movement.

None of the other exposure modes give me this.

I do sometimes switch to Program mode or Aperture Priority, if need to swing my camera continually between heavy shade and bright sunlit areas. But most times I want to be in control of my exposure metering for consistency and accuracy.

There’s a side-effect to using automatic metering that I’ve noticed among newcomers to photography – there is a tendency to blame the camera. It’s a subtle shift in mind-set, but it is there. Instead of assuming responsibility and learning about good technique, it becomes a quest for a camera that will do it all. With manual metering you are in control. So if there is a problem, you are the one that needs to figure out why, and how to improve on it. You decide. Not the camera.

Reasons for shooting in manual exposure mode:
– your camera’s meter relies on the reflectivity of the subject and assumes mid-tone grey. Even with matrix / evaluative metering your camera can only guess at what you’re trying to achieve.
– if you use Program or Aperture Priority while using TTL flash as your main source of light, your camera will vary your shutter speed between shots, and your ambient light will therefore vary.

You have to understand the limitations of automatic metering, whether in camera or with TTL flash – and that lighter or darker tones within the same picture area, will affect your meter. And you most likely don’t want it to. You want a lighter tone to appear light in the final photo. You want darker tones to appear dark. If it is an even mix of tonal values, then you’ll most likely get an accurate meter reading in one of the auto modes.

There is a specific reason why I don’t use general exposure compensation – I don’t want to adjust my exposure compensation every time I change my composition. BUT, I do use flash exposure compensation (FEC) all the time, when I use TTL flash outside of a studio. Since the reflectivity and tonality of the scene that my camera’s meter is reading changes all the time, I have to ride my TTL flash exposure compensation all the time … or much simpler, get correct exposure settings in manual exposure mode.

 

So how do I meter for correct exposure?

In film days I would exclusively use a flash-meter for flash. For available light I mostly just carefully used my camera’s built-in meter.

With digital, I still largely meter like that. But we have more tools available to us with digital.
So for me it has become an iterative process of:
– checking my camera’s meter,
checking the histogram
– and blinking highlights display,
– checking the image on the LCD, (although this isn’t an accurate assessment of exposure),
– experience.

There is no fixed recipe in approaching metering in all kinds of situations. It’s a mix-n-match of different techniques – all used to make sure I get optimum exposure for my images.

 

Ambient light, without flash

The reason why I strongly suggest shooting in manual exposure mode 99% of the time, is that for a specific outdoor scenario, the lighting normally doesn’t vary much. And by determining proper exposure, your photos will look consistent in a sequence of photos,
– regardless of composition, and
– regardless of how wide or tight you’re zooming, and
– regardless of the reflectivity of your subject matter (eg, lots of bright tones), and
– regardless of whether you have bright sky in a wide shot, or not, with a tighter composition.

If under the same even light and within the same setting, you’re shooting vertical and horisontal and wide and tight and from a high viewpoint and a low viewpoint … your exposures will vary unless you’re shooting in manual. It’s the ONLY way if you want to get consistent exposures.

With this consistency in exposure, your digital workflow will be much easier.
Even more so if you shoot in raw.

Now, that is for ambient light. Onto flash. This gets slightly more complicated. For starters, we have to choose between Manual flash and TTL flash.

 

Manual flash

If you have flashes set up that are in a constant position in relation to your subject, such as with in a studio setup, then the ideal way is to shoot with manual flash. Using a flashmeter for this is usually the easiest way to determine exposure. This will fix your exposure to your chosen ISO and aperture.

If you’re using on-camera flash and keeping in a static position in relation to your subject then it might be easier to use manual flash. This will once again keep your exposures consistent within a series of shots. With digital, you could do a few test shots, and chimp to figure out the correct exposure with your flash in manual. For a single photograph, it might just be simpler to shoot with TTL flash anyway.

Using a light meter with manual flash to get to correct exposure, is remarkably simple.

 

Auto / TTL flash

But as soon as you have flash on-camera, and you are moving around in relation to your subject, then you’re better off with some kind of automatic metering of your flash. This means using your flash in Auto mode or in TTL mode. It really will make your life simpler with digital photography, to not shoot with manual flash in this case.

But now we run into the problem that suddenly the flash output is affected by the reflectivity and tonal values of the subject and the scene. Remember, your camera’s meter will try and expose for any scene in the frame, as an average tone. Neither bright, nor dark. This is true for automatic flash as well. Which means you will HAVE to ride your flash exposure compensation to get optimum results with flash photography … if your flash is the dominant source of light.

If your flash is only fill-flash during daylight, then most likely the best use of flash will be as soft fill-flash. And in that case, the best results are usually with the flash exposure compensation dialed way down. And hence, the reflectivity of the subject will seem to have less impact on the exposure, since our exposure will be primarily for the ambient light.

When I shoot this way outdoors, I usually dial my Canon speedlights down to around -2 to -3 stops. But with Nikon strobes I tend to dial down less – usually around -1.3 or -1.7 … because I then use the Nikon speedlights in TTL BL mode, which balances flash automatically with ambient light.

But this also depends on how much flash we need to use as fill-flash. If we’re photographing someone in the shade, and we need to bump the exposure up to match a sunlit background, then we’re going to need a lot more flash. And therefore the flash exposure compensation will most likely be around zero.

There are no easy answers.
Anyone who tells you there is one magical do-all setting for flash, is lying to you.

 

Being ready is being half-way there

It is important that you start to anticipate things .. for example, if I am shooting indoors where my flash is my dominant light source, I’ll most likely be shooting at 800 ISO or thereabouts, and using a slowish shutter speed to get some ambient light in .. say around 1/40th or so, but it really depends on the scenario. I’ll also be using wide-ish apertures.

My Nikon SB-800 Speedlight will be set to TTL (and not TTL BL) and most likely have +0.3 exposure compensation dialed in … since it is the dominant light source in this set-up.

With Canon, this varies. With my 1D mk2 bodies, I usually kept my flash exposure compensation to
+0.7 as a default starting point. (I’ve heard of 20D shooters doing the same.) With my 1D mk2N bodies however, I’ve found that a default of 0 flash exposure compensation is best. (5D shooters have reported similar.) Also, with the 1D mk2(N) bodies, I have set Custom Function 14 to “Average”. I found that when my flash is the main source of light, that using “Average” here gives me the most predictable results.  But when I need to use the Canon flash for fill only, then I get more subtle results with the flash metering set to “Evaluative”.

Moving from dimly lit indoors to bright light outside,
I do three things as a matter of course as I step through the doorway:
– I dial down to my lowest ISO,
– I dial to my highest flash sync speed,
– and I set my aperture to an approximate value.

There is a specific reason why I gravitate towards my maximum flash sync speed.  There’s a certain sweet spot there in terms of getting the maximum range from your strobe. This is quite useful when you need to balance a subject which is in shadow, against a brightly lit background, for example.

If I had been shooting indoors at f2.8 and f4, then I will be needing smaller apertures outside.
For 100 iso, 1/250th, you’re looking at something like f11 outside … so I’ll set f11 and fire off a test shot or two at a general scene and chimp quickly to see histogram, and blinking highlights, and then fine-tune my exposure. All of this in a few seconds .. and then I’m ready.

Overcast days will mean a different aperture than f11 for bright days, but 100 iso and 1/250th is always my starting point for Canon D-SLRs. If it is heavily overcast, I’ll go to 200 iso, but I nearly always try to keep to as high a sync speed as possible.

With Nikon D-SLRs, my starting point is around 1/250th @ f10 @ 100 iso. This is because the there is a difference in the sensitivity of the sensors of the various camera manufacturers.

So moving from an indoors setting, as I step outside, my camera settings are pretty close to where I need to be. No fumbling for settings. I’m ready … because I anticipated what I’d need.

 

related articles

 

next section:  flash exposure compensation

 

video tutorials to help you with flash photography

If you like learning by seeing best, then these video tutorials will help you with understanding flash photography techniques and concepts. While not quite hands-on, this is as close as we can get to personal instruction. Check them these and other video tutorials and online photography workshops.


 

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{ 43 comments. } Add a Comment

1 Rob March 4, 2010 at 5:26 am

Neil, thank you for the most common sense, practical, straight forward blog I have seen. I have been to workshops, and read, and ask .. I am a fulltime photographer who loves to learn.. and your style of common sense explanation, and practical “what works for me in real life” approach, is a breath of fresh air. I live in Sandton, in tha land of your origin .. wish I was closer to be able to do some practical workshops with you. Well done .. whatever you get, you deserve.
Rob Milne

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2 Scott Viney March 19, 2010 at 1:38 pm

Hi Neil,

Thankyou for the information on this page. I have a question about the ambient light. What about if you’re indoors? What tips have you got for this? Because if you are photographing an event for example, a birthday party. You might have a large window and the lights will be on. So as you go deeper into the room you have less light from the window but the room light might be over head of the subject. Or grandma might be playing with the grand kids between the window and the main room light…So again different exposure. Am I missing something here? What do you do as a professional in this situation?

Thankyou for all your help,
Scott

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3 Neil vN March 20, 2010 at 3:35 am

Scott, this would be typically where I allow TTL flash (bounced) take care of the difference in ambient exposure.

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4 Miranda April 16, 2010 at 1:45 pm

Thank you thank you thank you.

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5 Steph June 17, 2010 at 4:42 pm

Very informative! The one thing I am struggling with though is I still want to shoot wide open outside to get the nice shallow dof efftect but how can you do this using flash to fill if the max. shutter sync is 1/125? I usually have to shoot over 1000 in alot of circumstances outside when using an f of say 2.8. I know in my D300 I can set it to high sync, but does that cover over 1/1000? Is the flash still working as it should in that case? I’m still getting the hang of flash for fill outdoors!

Thanks!

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6 Neil vN June 22, 2010 at 11:14 am

With the D300 you can sync up to very high shutter speeds. Enable ‘Auto FP’ on your camera by setting custom function E1. A simple check will show you that you can sync to at least 1/1000

However, with high-speed flash sync, you lose a lot of power from your flash. You will have to move your flash a lot closer, or add a second flash.

I’m unsure what you mean by your “shutter sync” being 1/125 ?

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7 Ian Smeatham August 10, 2010 at 6:12 am

Hi Neil.

Nice talking to you before, this was the article I meant, the last section (Being ready is being half way there).

Very handy, so much of your advice is real world stuff about actually taking pictures – which is very refreshing.

Off to amazon now to check out your book..

Kind regards
Ian from Liverpool, England

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8 Gary Smith September 29, 2010 at 6:48 pm

Hi Neil,

Many thanks for sharing your knowledge with us all. Your work is an inspiration to me in my fledgling wedding photographic career.

I have a question about your metering technique.

Do you just use the central weighted or spot metering on the camera or do you zoom into the dress to get the exposure and then zoom out and recompose the shot?

Kind regards,

Gary

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9 Neil vN September 29, 2010 at 8:04 pm

Gary .. thanks! Regarding which metering mode to use – ultimately it doesn’t matter, as long as you meter correctly. It’s the thought-process and method that is crucial. Also make sure you read through the series of articles on exposure metering.

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10 Arran Moffat Edinburgh Photography January 27, 2011 at 9:22 am

Hi Neil. Your blog is an excellent resource, particularly as I’m new to strobes. Fantastic! Keep up the good work. Bye bye Aperature Priority Mode, hello Manual Mode.

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11 Hisham/Egypt March 7, 2011 at 1:54 pm

Hi Neil, Is my understanding right?
You have here two environments:
1- Outdoor ambient light, use camera built-in metering, choice open to use manual mode when ambient is constant OR use TTL-BL when moving (to solve varying reflectivity issue) adjusting strobes power as needed(-1.3 or -1.7 etc), then apply proper FEC as needed.

2- Indoor or Studio, use flash-metering(not camera metering), use manual mode as studio lighting (On camera/Off camera) is stable, no FEC needed.
Is this true Neil! Many thanks to u, I consider this post one of the best. *&*

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12 Neil vN March 9, 2011 at 10:23 am

Hisham .. you’ve nailed it. Also check out this Flash Photography tutorial, just to reinforce the idea.

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13 James Basire May 12, 2011 at 2:16 pm

Hi Neil,

Your website is amazing! Full of good straight forward facts which I haven’t been able to find anywhere else so thank you very much for all your help.

I’ve a question. You say you don’t use Av (Aperture Priority) or Tv (Shutter Priority) Modes and use Manual near exclusively. I shoot a Pakistani wedding on Sunday where I was shooting in and outdoors covering the arrival of the bride and then separately the groom. Movement was quick from the subjects facing the sun to having their backs to the sun and then again indoors in different rooms (as bride goes to a separate one to groom) with different levels of light, ceilings etc.

Starting with the outdoors facing the sun would you normally take a camera meter reading for the background then put that into the manual mode on the camera and using TTL, then take another reading for those with backs to the sun and input manually using TTL and repeating also inside for each room you go into all the while riding the FEC for each situation?

Many thanks
James – London UK

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14 Roy Barnes May 15, 2011 at 7:36 am

Hi Neil
Quick question: I shoot with film (yeah – I’m one of those that lives in the past!)and these days I only have access to 400 speed film. Using the f/16 rule I’d need to shoot at 500/s @ f/16….4000/s @ f/4. Given that my camera has a synch speed of 125/s how can I – in setting my shutter/aperture manually – shoot at the synch speed AND retain a narrow depth of field? Or it simply that I have to resort to using high-speed flash?

cheers Neil

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15 Neil vN May 15, 2011 at 12:57 pm
16 Brad June 29, 2011 at 7:45 am

Neil

You keep referring to “Chimp” or “Chimping”. Can you please explain this term. My apologies if I have missed something.

Cheers

Brad

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17 Neil vN June 29, 2011 at 9:48 am
18 Ken September 12, 2011 at 12:12 am

I used an external (as in not built-in) flash few weeks ago. With a few trial shots (the function was about to begin) I managed to get to a manual setting where i could adjust the shutter-speed and aperture by a stop or two to get variations in depth and exposure.

I am now a fan of manual exposure :)

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19 John Woods October 6, 2011 at 2:49 pm

I read that the location of your focus point while composing affects your ETTL metering. I’ve tried to replicate this, just spent the last 15 minutes taking pictures of my fireplace, and my results are inconclusive. Does it make a difference to my ETTL metering whether I focus on the dark firepit or the light colored marble around it?

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20 Tony Sale October 16, 2011 at 5:37 pm

This is I think one of the most useful posts you have written (they are all good) but this is always a great starting point and one I often come back to. It’s the foundation on which everything else follows. Thank you

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21 Lulie Tanett November 9, 2011 at 8:28 pm

>> “- checking the image on the LCD, (although this isn’t an accurate assessment of exposure)”

Why wouldn’t this be the most accurate assessment of exposure? Is there really that big a difference between viewing it on a small LCD compared to a big computer monitor?

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22 Neil vN November 9, 2011 at 8:32 pm

Lulie … just see for yourself how a well-exposed image looks on the back of your camera’s screen when you’re indoors in dim light, compared to stepping out in bright sunlight.

While we often rely on the camera’s preview, and often *have* to rely on it, the camera’s preview isn’t necessarily the best way to make a judgement on the image’s exposure.

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23 Amy Eko December 10, 2011 at 8:15 pm

Neil,

I am trying to wrap my brain around what takes priority when choosibg settings outside. I am doing a family portrait in the next couple of days,, but the weather has been severely overcast, so when I was taking some sample readings today (I believe the light conditions will be about the same) I was coming up with 1/250, f 8, iso 2000, I am using a d700 with the 24-120 f4 lens. I chose 1/250 because it is the max sync speed and also to help prevent camera shake, I chose f8 because I want to make sure all the faces are in focus. This left me with a rather high iso of 2000. Do I have my priorities straight? Would you perhaps drop shutter speed down so that the iso could come down a bit? I don’t really want to change the aperture much. Too mant times I have had the frustrating result of having one family members face out of focus because my f-stop was too small. Thanks.

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24 Neil vN March 2, 2012 at 6:11 pm

Eko .. assuming you’re using those settings so you can balance your flash with the ambient light .. well, then that is far too high an ISO for a group photo where you need detail.

You will have to bring your shutter speed down, and find a way to stabilize your camera. A tripod is a good idea. Simple as that. It’s the best way to juggle that shutter speed / ISO / aperture combination in this case.

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25 Lindie March 3, 2012 at 11:36 am

“Moving from dimly lit indoors to bright light outside,
I do three things as a matter of course as I step through the doorway:
– I dial down to my lowest ISO,
– I dial to my highest flash sync speed,
…”

Please explain why you don’t use highest flash sync speed indoors by default.

Many thanks

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26 Neil vN March 4, 2012 at 6:12 pm
27 Lindie March 5, 2012 at 3:09 pm

Would love to see Neil’s comment on Amy Eko’s question. Suppose she needs extra light sources?

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28 Neil vN March 5, 2012 at 6:14 pm

The problem in that scenario isn’t that there isn’t enough flash, but rather that the ambient light isn’t very bright. So adding extra flash / additional light sources to the subjects, won’t help the balance of flash vs ambient in this case.

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29 Robert March 25, 2012 at 10:46 am

I’m still a bit fuzzy on the concept of using a camera’s max sync to allow your flash to work at its most peak efficiency when shooting outdoors in bright conditions.

Wouldn’t dropping your shutter speed below your max sync speed let more ambient light into your exposure and in turn decrease the overall amount of output your flash would need to produce at a given distance to fill in shadow areas?

Rob

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30 Neil vN March 29, 2012 at 6:31 pm

There are so many different scenarios we can find ourselves in, that it isn’t easy coming up with single solution. Let’s assume we’re balancing flash with ambient light. (ie, the flash isn’t doing the heavy lifting here.) In that case then, if you drop you shutter speed, you over-expose your ambient.

Go through this article as well: Flash Photography tutorial. It covers a lot of the same topic.

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31 Pete (London) May 1, 2012 at 8:54 am

Hi Neil,

Add me to your fan base, I’m truly grateful for all the information you put out on your web site. I’m all fired up with my recently 430ex and I’m practicing a lot.

I’ve recently come across these 18% grey cards. To me, manual metering then becomes a simple case of lining up the pointer in the view finder to its zero/middle position. Just wondered what you think about this? Am I being to simplistic here?

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32 Neil vN May 1, 2012 at 10:37 pm

Pete, it absolutely does make sense. I used to meter like this when I was shooting 35mm transparency film where there is no wriggle room with exposure. It has to be nailed, spot-on.

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33 Pete (Barnet, uk) May 5, 2012 at 7:14 am

I’ve switched back to manual metering now, you reasoning makes so much sense and it’s what I did in the olden days when cameras weren’t so automatic as they are now. I just got lazy and just used AV mode all the time.

But I can see that some situations where you have to react to events that change fast (ie a school sports day) then Tv or Av does make sense.

My question is regards auto-iso. My Canon 7d has this feature and it uses a sensible range of iso. So does it make sense to let the camera control the iso while I dictate shutter and aperture?

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34 Neil vN May 9, 2012 at 6:50 am

Auto-ISO just brings back a variable, that goes counter against the idea of shooting in Manual Metered mode. Also, if you use off-camera flash in Manual mode, then auto-ISO will mess you around.

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35 Francois March 6, 2013 at 8:12 am

When using the Histogram to set your White Balance:
What if you don’t have white on the subject to fix your exposure on the histogram? Say the lightest color is her face – Do you still then push her face (the brightest color on the subject) to the right of the histogram – to the same position where white would have been?

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36 Neil vN March 7, 2013 at 12:22 pm

The idea with using the histogram for exposure confirmation, is to have the area that has the brightest tonality, ie, white, be on the edge of the histogram. Then the rest of the tones will fall where they will (have to).

If you expose for skin tones as if they are a pure white tone, then you will over-expose.

So you could meter of skin tones, but then you will have to interpret how bright they are relative to “average” and to “white”, and guess an exposure for them. It becomes easier with practice.

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37 Stacey April 3, 2013 at 3:24 pm

Neil – I’m still reading your blog over and over… learning all the time.

I’ve recently shot a few weddings, and I almost exclusively shoot in spot metering on my 5D. I find that I get the results I want when outside or creating a more arty shot. However, at the reception and on the dance floor later, I find results very inconsistent. Could this be because of my over-reliance on spot metering? Do you think I would get better results in these fast-moving situations by using evaluative metering?

Thanks!

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38 Neil vN April 3, 2013 at 10:28 pm

Stacey … what exposure mode are you using with your camera?
And do you specifically meter for the ambient and then add flash?
What’s the way you work here?

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39 Stacey April 4, 2013 at 12:01 pm

Neil – also, can you confirm exactly how you meter for ambient light. I tend to zoom in/point to the back of the room and meter; then zoom/point back out to re-compose. I suspect I am doing it wrongly for the results I am looking for (i.e. much like yours).

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40 Neil vN April 4, 2013 at 10:30 pm

Stacey, again, you’ll have to give us more details. What are you photographing and what is the scenario?

For a longer discussion (and a place to upload images), join us on the Tangents forum.

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41 Stacey April 5, 2013 at 2:38 am

Hi Neil – I am capturing the first dance of the bride and groom. The room is uniformly dark with just a few tungsten lights and DJ lights.

I am using spot metering on manual.

I turn off the flash, point the camera to the back of the room and take a reading of the ambient light which falls there. I zero the meter then turn down a stop or two. I then switch flash on (+1 or +2 FEC).

But, I still get very underexposed images. I rectify them in RAW workflow, but I’d like to get it right in-camera. I suspect that I should not use spot metering for this purpose, but any suggestions…?

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42 Neil vN May 24, 2013 at 10:33 pm

You do not have to center your camera’s exposure meter when shooting in low light with flash.

There are two exposures taking place: ambient + flash. If you under-expose the ambient, the flash will pick up the difference.

That you’re not getting enough light means your ISO is too low, or aperture too small … or you’re not bouncing flash correctly.

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43 CY March 23, 2014 at 9:26 pm

great article. please help. im on manual mode – so my ambient exposure is fixed. how would the flash in TTL know how much power to fire? does the metering evaluative vs spot metering help?

i looked over some of my past shots – when my subjects wear white, there isnt enough light being fired by flash. but if my subject wear black, sufficient light was fired.

can i compensate by just increasing the FEC on the flash in TTL

ps: using canon

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