Lighting 101:Balancing Flash With Ambient, Pt 2
When last we met, we talked about the idea of balancing strobe with ambient. We were using the strobe as a main light and the ambient as fill, but you do not always have to do it that way.Straight fill flash is very simple these day, with TTL flashes doing the heavy lifting for you automatically. But doing it the easy way usually means keeping the light on the camera, or using a TTL cord. These little cords tend to make the light come from a consistent position on the left side of the frame because that's where Darwin stuck your left hand.
The goal here is to start to replace the concept of 'fill flash' with that of 'balancing light.' And, more importantly, to separate the ideas of fill flash fill/balance from the rote use of on-camera flash.
The process of using flash to augment (which is a better concept than fill) sunlight is very straightforward. First you are going to start at your camera's highest synch speed, because that'll get you the most flexibility from your small flash. While you're at it, dial your ASA down as low as it will go to get better quality and avoid those CCD-chip dust spots, too.Now think about your lighting angle. As opposed to the idea of fill flashing, on-camera, from any angle outside without regard to the sun's direction, using a strobe on a stand effectively gives you two lights to play with. You can balance. You can cross light, You can do both. You'll have more flexible (and consistent) results using this approach.
When you just fill flash from on-camera, it does bring up the shadows. But while the flash adds detail it really misses out on the opportunity to improve the depth and quality of the light. So why not do both at the same time?
Step one: Think of the sun as your main light, and your strobe as a secondary light. You are not just getting rid of raccoon eyes now. You are working with two lights. You have flexibility.
Choose your angle of attack. Maybe you have the sun behind you (on the left side) at a ~45-degree angle. Why would you have your fill on on camera when it would look better lighting from the upper right? On camera flash limits you. All the time.
Maybe you turn the angle around and shoot the subject in profile. Say he is facing to your right. You could have him looking into the sun, which is now angled to come from slightly behind his face to provide nice (but too contrasty) rim light. Just move your strobe over to the left side, elevate it a little, and you have a cool-looking, two-light setup.
Whatever the angle, the technique for balancing is the same. We are basing the exposure on the ambient this time, and bringing the flash up to fill shadows and/or provide light from another direction.
Assuming a sunny ambient to balance, set your camera at the highest synch speed (i.e. lowest aperture) to ease the burden on your flash. Now, get your base (ambient) exposure. We'll call it a 250th at f/11 at ASA 200 for the sake of argument.
Now, with your strobe on manual and on a stand, set it to somewhere around a quarter to half power if you are working close. Maybe half to full power if the flash is further away. If you are not lighting a large area (and you usually are not) zoom the flash to a 70mm or 85mm lens angle to make it even more powerful.
Pop a test frame and eyeball it. If your flash-lit area is too bright, dial the flash down or move it back. If it is too dark, dial it up or move it forward.
This is a fast, simple technique that works great. No flash meter needed. Full manual for a consistent shoot.
The important thing to remember (and why I told you the angle stuff first) is that this is now a starting point to turn your outside "fill" strobe into a true, useful second light source. Experiment.
One of the most useful
Outside? Play with fill light and angles. (You might want to grab something safe in the shade first just in case.)
Inside? Set up a quick umbrella in a corner where one wall is your background and another is your fill card.
You'll turn a mug shot into a head shot, which is just a more professional way to do it. You'll get some good (low-pressure) experience in your lighting. And they'll look better in the paper. It's a win-win.
And, contrary to what you might think, most people will be secretly flattered by the effort you are putting in to making a better photo of them.
And one more thing. Stop thinking of them as mug shots from this point forward. A
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37 Comments:
Okay, I've been reading about (or trying to read about) balancing ambient with flash and whatnot. I have officially gotten a headache, tried to make sense out of what little info I can find out there about this balancing act, and anything else just talks about letting the flash do the math. Something I'd like to get away from so I feel like I'm actually doing something with my pictures and not the damn camera.
I think I've done everything I can do avoid asking any questions. I like to figure this stuff out myself, but...I must give in.
Using the FLASH as FILL...
Set the camera to its highest sync speed (in my case 1/250th). What I think is confusing me is the bit where you say "(i.e. lowest aperture)."
In this case, set the highest sync speed and then the lowest aperture for the ambient light?
In the example you used, 1/250 @ F/11 ASA 200. You set the f-stop based on the available light at the time?
And then just adjust the flash to your liking (1/4-1/2 or 1/2 to full depending on how you want it to look).
Is it safe to say, if you have a high speed sync option (using a Canon 20D with Speedlite 580EX), I could set the shutter speed faster if I needed to and start to sacrifice dof?
...sound right? I think I've got a grasp on it, but my hands are buttery...so someone throw me some toast!
You have a better grasp on it than you think. Using your highest synch speed (whether a 250th or a 500th or whatever) will allow your exposure to be a a MORE WIDE OPEN (less confusion) aperture.
Thus, you flash can light your subject with less output, happier batteries, shorter recycle times, etc.
If your light levels are low, you have plenty of options, but outside in the sun you want to aim for the high sych speed and go from there.
I've gotten the whole balancing fill with ambient thing down. I can pretty much nail a seriously backlit shot in one or two frames thanks to all the advice I have gotten on Strobist.
Here's my problem: I shoot sports events: Running races and triathlons. Last weekend I had to fill swimmers coming out of the water. 900 came out over 40 minutes with 30 per minute at peak. At 1/16 power I shot about 100 frames and began to smell plastic burning. Sure enough, the lens of my EX580 had melted. I switched to metering the swimmers and tried to angle the sky out of the shot to keep from burning the image.
Yesterday I was shooting bicyclists. The 580 being in the shop I was using a 550 at 1/8 power on a very crosslit road. At peak times 15 cyclists per minute were going by, some in packs of 3-7. The first problem was that even at reduced power and with an external pack the flash could not recharge fast enough between shots. And then the head began to get warm and I had to back off shooting every cyclist and had to go for every other or every third one. I'm supposed to get every one.
So, I need a head that can recharge sub-second, take up to 20 shots per minute, and do that for up to an hour without melting. Probably does not exist, does it.
Another thought. Set up a "tree" of 2-3 SB24s/26s or Vivitar 283/5s on a light stand off to my side each wired to a Pocket Wixard Multimax and use the 'sequencer' feature fo set them off one after the other. It might give them enough time to recharge fully and cool off. The athletes are pretty much in a fixed path so I can regulate the output for when they get to a given point.
Other than that, I'm stumped. Rapairing melted 5XX heads is getting expensive.
Suggestions appreciated.
Ken
You need something that is designed to handle the punishing duty cycle you are putting a flash through.
I'd look for something that does not place a fresnel lens in front of the flash tube, as do just about every shoe-mount flash. That's your heat bottleneck.
A Lumedyne flash, or a Quantum Q-Flash would handle that kind of stress.
I'd like to respond to tim's comment above. For the past couple weeks I've been reading on the internet, trying to understand flash exposure and how it relates to ambient exposure. I read on another useful site where a photographer mentioned that the aperture directly controls the flash exposure. Now, I understood fully ambient exposure...how shutter speed, film speed (or ISO), and aperture all relate to a proper exposure. But my brain would melt faster than an overused 580EX when it came to understanding how my Elan7 would try to control my hotshoe flash...."automatically" adjusting to ensure a proper flash exposure. Just the thought of it drove me crazy. I imagined that flash atop my camera, running amok with whatever output it wanted.
Then I started reading where 'pros' were recommending you set your flash to manual to set the flash exposure. Why, damnit, why? Then it hit me, lying in bed at 11:30pm three nights ago. Just as shutter speed and aperture (time vs. size of opening) affect exposure...the same must be true of flash exposure. But how? Then, I got it...the length of time of the flash on manual is a fixed interval So of course the aperture size directly controls the flash exposure...the flash time is fixed. Want less flash in your picture?? Make the hole through which it passes smaller, lower the output of the flash (turn down the volume), or move the flash further from the subject.
Warning: here's where I'm talking out loud so that I understand it better myself.
So now, when you use a high sync speed (1/250, for e.g.), you're not giving your camera much time to expose for the ambient portion of your photograph. If you use a high aperture, you're restricting that lite even more. So, if you wanted to create a pool of light around your subject in strong daylight...use a high sync speed (reduces ambient light), a small aperture (reduces ambient light), and adjust your flash (by either turning up the power, or moving it closer) so that it can pump out enough light to illuminate your subject.
I love this website!
Best, Eric
ericrudd: You wrote that to create a pool of light in daylight you should 1. use a high sync speed, 2. use a small aperture, and 3. increase power on the flash and move it closer. Numbers 1 and 3 are true, number 2 is not relevant. Reducing aperture reduces the flash contribution and the ambient contribution equally. Ditto for changing the film speed or using a faster/slower lens. This article spells it out:
http://www.kenrockwell.com/tech/syncspeed.htm
Hi,
I've been reading Balancing Flash With Ambient and I'm a bit confused. My brain (such as it is) reads your text as saying that I can meter the ambient light in a given situation. Then, set the flash to put out light 2 stops under that ambient reading: using a synch speed 2 stops higher than the ambient reading. This is where I get confused. Say, for example, my ambient reading is 1/30 sec and f5.6. Are you saying that I should use a setting of f5.6 at 1/125sec or the highest synch speed which, in my case, would be 1/2000 sec?
>Numbers 1 and 3 are true, number 2 is >not relevant.
I appreciate the clafication. It helps me wrap my brain around this too!!
Thank you!
eric
David,
you mentioned to create a lighting ratio by
dropping the ambience lighting down 2 steps
This can be achieved in 2 ways, either closing up
the aperture, or increasing the shutter speed.
Either of which affects the Ambient exposure hence
the lighting ratio...
And here I am reading Ken Rockwell's article on sync
speed (http://www.kenrockwell.com/tech/syncspeed.htm)
stating that "lighting ratio is only affected by
DIstance, Shutter speed and Flash power". (Not affected
by aperture???)
My understanding of it is, given a fixed shutter speed,
if I opened my aperture, wouldn't I allow more
ambient light, hence change the ratio anyway?
Someone help clear my confusion...
Julius
Julius,
You should remember that Apiture, shutter speed and ISO are all inter-related. Your staement is correct, if you open the apiture, you will allow more light to fall onto your sensor.
A lighting diagram would go a LONG way here:
Maybe you turn the angle around and shoot the subject in profile. Say he is facing to your right. You could have him looking into the sun, which is now angled to come from slightly behind his face to provide nice (but too contrasty) rim light. Just move your strobe over to the left side, elevate it a little, and you have a cool-looking, two-light setup.
I have read this several times, and I just get more frustrated every time I read it, because I cannot picture what is being described.
No comprende.
Julius,
Your ratio is how much light is brought in from one light source compared to how much light is brought in from a second source.
Opening or closing your aperture increases or decreases the light received from both sources but doesn't change the ratio of one source to the other.
Shutter speed does affect the ratio because the longer the shutter is open after the flash is finished contributing light, the more ambiant light your sensor will receive in relation to light supplied by the flash.
The best part about this post is that no one here has any clue who the person is on the first shot. How did you get to shoot RP?
Anon-
I got to meet many, many interesting people in my work as a newspaper photographer.
-D
These little cords tend to make the light come from a consistent position on the left side of the frame because that's where Darwin stuck your left hand.
I think the light comes from the left side of the frame because there are no lefthanded camera's ;-)
Daniel B. said:
Hi David,
Your first picture grabbed my attention not so much for its lighting, but for the fact that the guy looks exactly like Prince Reza Pahlavi son of the former deposed Shah of Iran "Mohammadreza Pahlavi"!
Is that him?!
That's exactly who it is. Very personable guy, too.
-DH
do you have any thing on picture style like, sharpness, contrast, color saturation,and color tone.
C4mike
First off, I started reading this (again) after 10pm, which is a bad idea. I love this website and it will and has already revolutionized the way I shoot. I haven't been shooting that long, but long enough that I'm surprised that this wasn't something I already knew: The duration of the flash can be a different length than the amount of time that the shutter stays open. Or in other words, a quicker strobe-time within a longer shutter-time allows the ever-present ambient to expose more. It sounds so obvious as I type it. Thanks for spelling things out for the math-challenged!
the light come from a consistent position on the left side of the frame because that's where Darwin stuck your left hand.
Darwin had nothing to do with my left hand.
For Pete's sake, "anonymous"-
It was a joke...
This post has been removed by a blog administrator.
@MiriamJ
I read Ken Rockwell's entire page about sync speed, and I just didn't get why the aperature didn't affect how much ambient light is let in. I couldn't understand it, until you said that aperature controls how much light comes in from BOTH sources, while shutter just from ambient. Thanks for clearing that up for me! It's like a light bulb went off.
Is there a way to know exposure in a room with out the light meter? do you just go by what your camera is telling you? I lack the capacity of walking into a room and saying "this is 1/10 sec @ F/2.8 (ISO 400)." does practice make perfect?
Krockwell's often overthetop sarcastic comments come from the point of view where you have already maxed out your synch speed and are trying to use less flash power, or you need more flash power or range. He is also assuming that you want to keep the ambient level where it is, and keep the flash distance where it is. In this case, if you were to open up the aperture, you would have to reduce the ISO and vice versa, either of which would result in the same flash power being used - a long winded way of expounding on his point that having a faster flash synch in daylight is very desirable.
"The duration of the flash can be a different length than the amount of time that the shutter stays open. Or in other words, a quicker strobe-time within a longer shutter-time allows the ever-present ambient to expose more."
I think what he means is the RELATIVE duration of the flash differs with the shutter speed... just wanted to clear that up cause the me of last week would have been completely thrown off by that comment. The flash emits for the same amount of time no matter what and varies only in strength, correct ?
David,
I use a Lumedyne(50/100/200/400ws) flash w/ bare bulb or reflector.
First I meter the ambient light and then use a flash meter so that I can match the flash output to the f-stop reading. The light looks like it is wrapped around the subject as if from one source.
Oops, the second half of my post went awol.......
David,
I use a Lumedyne(50/100/200/400ws) flash w/ bare bulb or reflector.
First I meter the ambient light and then use a flash meter so that I can match the flash output to the f-stop reading. The light looks like it is wrapped around the subject as if from one source. I set the flash on a tripod to keep the flash to subject at a constant f-stop. I also use a Quantum 4 radio-slave to fire the flash.
David,
You wrote, "Maybe you turn the angle around and shoot the subject in profile. Say he is facing to your right. You could have him looking into the sun, which is now angled to come from slightly behind his face to provide nice (but too contrasty) rim light. Just move your strobe over to the left side, elevate it a little, and you have a cool-looking, two-light setup."
Am I the only one that doesn't understand this. I'm trying to visualize, "him looking into the sun, which is now angled to come from slightly behind his face" and I just don't get it. I thought the sun was behind me at 45degree angle to my left. That would have the sun pointing to the subjects right side of their face. Am I changing places with the subject at some point. Is that what you mean by "turn the angle around"? I'm confused. Please explain or add a visual. Thanks.
To sync a shutter with a strobe is to determine when the strobe fires: when the shutter is wide open. It does not usually throttle the amount of light emitted by the strobe. Lights go on light stands; cameras go on tripods.
David, I am really enjoying your blog. I spoke with Moishe earlier this week. He tweaked one of his kits to meet my request. It shipped yesterday. I have been away from the craft for quite awhile (I shot weddings on a 4x5) and am eager to begin using your suggestions.
One more word on shutter speed. The 1/60 "flash" setting is left over from flash bulbs, predating strobes. The relatively slow speed was to give the bulb time to burn up to its brightest. Any motion during the exposure would cause a blur.
Thanks David,
I get the value of using manual settings n the flash. But why not use wireless iTTL (Nikon CLS) to help get an initial reading -- and then use the minus or plus ev settings available for that mode to fine tune? Would this not be a good shortcut to estimating the initial setting?
Joe
David,
This is in responce to Daryl's comment of March 20th...
"To sync a shutter with a strobe is to determine when the strobe fires: when the shutter is wide open. It does not usually throttle the amount of light emitted by the strobe. Lights go on light stands; cameras go on tripods."
When using a Lumedyne Flash you have the choice of 4 different watt seconds (50/100/200/400). Each one puts out a specific flash intensity, thereby allowing you to regulate the amount of light you need to properly expose your images. Since this light is for fill purposes, as long as you stay within the guidelines of your camera's off camera flash settings for shutter release, you can pretty much set the flash to go off anytime while the shutter is open (first-middle-last). Lumydyne does not sync with the shutter.
As far as the tripod/light stand goes, my tripods have a quick-release mount that allows me to switch between hand held or stationary, rapidly. Both my camera and flash use quick-release.
Besides, I find that tripods are more stable in windy conditions and also can be leveled more accurately.
Thanks.
after reading the article, http://www.kenrockwell.com/tech/syncspeed.htm
it seems that a sync speed of 250 is a starting point and ideally, you would want something at 500 or higher...i have a canon 10D and it has a sync speed of 250...i researched the newer models (50D and 5D) and the tech specs say they have a x sync at 250...are canons maxed out at this speed and therefore unable to do some of the high sync shooting in sunlight?
You are correct about the Canon's, ralston. However, I believe I read that the new PocketWizard MiniTT1 will allow a sync up to 1/8000.
After close to a year I think I finally got it. Sometimes this sounds like math to me and I don't do math. Basically set the camera to underexpose the image, use the flash to correct the exposure. See? No need for words like 'ratio'. Now I can try this.
Thanks.
Thanks David, all I've been doing with my flash up until this point is bouncing it off ceilings and walls when it's too dark inside for my slow lenses.
I've been reading your blog over my lunch breaks, and when I get home from work I rush to my camera and flash to try out the new techniques I've read about. All the guys complaining that you haven't explained it clearly enough, I think could not have possibly tried the techniques in practice, because all the fog in the understanding becomes clear after a few test shots!
Great blog, and thanks again.
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