On-Axis Fill: Run-and-Gun Version
Actually, I have had had five- or even six-assignment days on occasion. But thanks to my therapist, I have learned to repress most of those memories. (Calm blue ocean, calm blue ocean...)
Days like that are a recipe to just say "screw it" and shoot everything available light. Or on-camera bounce flash. But it doesn't have to be that way. And on-camera fill against off-camera flash is one technique that would have been a tremendous help to me as a newspaper shooter on those days from hell.
Keep reading for one way to light when you don't have time to light.
Hey, What's This Flash Bracket Thing on Top of My Camera?
Okay, let's be clear here. I am talking about direct, on-camera flash. And before you jump all over me, think about what on-camera fill flash is designed to do: Tame the shadows.
The problems -- the sameness -- that results from typical "3-D, matrixed-balanced, whizz-bang TTL fill flash" when it is used on-camera for ambient fill is that you are still at the mercy of your available light. The flash is merely there to fix the eye sockets. Or whatever else is going too dark.
But we can take that straight fill concept one step further, and add it to light that we have designed. In this environment, bare, on-camera flash can do some cool things for us.
When I say "on-camera," I am talking about either a shoe flash or a pop-up -- either can do the job. But the key difference is that we can use this flash as a third light source if we have a second flash.
For people who own a pop-up flash camera and a shoe-mount flash, this is a great run-and-gun setup. The on-camera flash gets used the same way a ring light would be used -- while crappy as a main, it is pretty cool as fill.
When I say "third light source," I am including the ambient as one of the first two sources. Which means if you have two shoe-mount flashes (or a single shoe-mount and a pop-up flash) you have a three light setup at your disposal. You just need to design the light so all three sources are working for you in concert.
Let's back up. If you are pushing on-camera fill into directional ambient light, you are doing one of two things: You are either filling angular front light or filling a backlit situation.
With the former, you still have no edge lighting to give you three-dimensional form. With the latter, you are basically key-lighting with direct, on-camera flash. Neither is going to be very interesting, and you will have very little control over your exposure choices, either -- it is either right or wrong.
But when you introduce a second flash (which means a third light source) you get the ability to cross-light and fill at the same time.
Take Me to the River
Let's do a walk-through of the above photo as an example. I was shooting a graduate school project to assess the health of a local stream. The light was what I would formerly consider horrible: Mid-day, high, back-ish overhead sun in a mottled, wooded environment.
If I fill that using only on-camera flash it is gonna look like crap. Well, maybe not crap but certainly not very interesting. No, check that. It'll look like crap.
And if I turn around, stick the sun behind me and fill it on-camera, it looks like every other fill flash photo in the back of every camera brochure in the world.
My goal in this setting is to use the sun as my backlight. Why? Because the exact lighting angle does not matter nearly as much as it would if I used it as a key, and it does not get in peoples' eyes. So no squinting.
Given that I am gonna backlight with sun and key light with off-camera flash, I can choose to set the entire scene at any tone I want. Start at a 250th of a second shutter speed to get a friendly aperture. Then dial that aperture around until I see a nice look for the environment. For me this usually means underexposing the ambient by a stop or so.
Essentially, I am exposing for the highlights, as if I were shooting chrome in the old days. (Back when we had to walk to our assignments, barefoot, in the snow, uphill, both ways.) Except that this time, we are not gonna let the shadows fall off the table into the deep, black abyss.
My back light and full scene established with the manual ambient exposure, I can now think about the key light. Since I am walking around on slippery rocks with a few thou in camera gear dangling from my neck, I am gonna go handheld and light them from the left side. Nothing fancy, and no stands. Camera in right hand, flash in left hand.
I normally shoot manual flash, but I am perfectly willing to use whatever mode works best for me in a given situation. So in this case, I stick the flash on TTL. (WTF? On-camera and TTL?)
Yep. For the flash, anyway.
I am in manual mode on the overall exposure, which means a straight TTL flash will be neutral. If I were underexposing the ambient by one stop in shutter priority (to keep a constant 1/250th of a sec shutter speed) I would juice the TTL flash by one stop to compensate for the overall "-1 stop" exposure compensation. That's just the way the camera settings work.
Now, if I TTL my flash (using, say, an off-camera TTL cord) then any frontal area that is not lit by the flash (or the sun) is gonna be very dark. That includes up under chins and the camera right sides of Charlotte and Chris, my stream diggers du jour.
And the more I saturate that environment the more the flash shadows are gonna drop. This will make the scene look very "flashed" and the overall lighting will look very harsh. But the object here is more legibility, a more natural look and total control of the various tones in the whole photo.
That's where the on-camera fill comes in. By dialing that in fill to, say, minus 2 1/3 stops, I can keep my lighting controlled and see up into my shadows. This gives me total control over three light zones of the photo: Environment/backlight, key-lit areas and fill areas.
Take a look at the lit areas up close in this sectional detail of the photo above. Examples of the fill areas would be the shadow side of Charlotte's face and under Chris's chin. Key light areas would be anything that is lit from camera left.
Environment is controlled by overall exposure. Key is controlled by the relative (+-) TTL setting on the key flash. Fill is controlled by the relative TTL setting on the on-camera flash.
If you look at Chris's neck, you can see both a fill area and a small, very dark, no-flash area that shows you how deep all of the key shadows would be without the on-camera fill. You can also see the no-flash area Charlotte's chin. Imagine all of the key shadows being that dark. That's the difference between on-camera fill and not, when key lighting off camera.
Yes, you could do this with manual flash very easily if you are not moving around too much. But this is a good example of when to offload that extra thinking and minute control in exchange for mobility. When you are looking for good footing, you can just find a safe spot, compose and zoom to compose. The camera and flash will get it pretty close. If it misses, adjust the key or fill TTL level to taste.
Two light modifiers are being used here: I have a dome on each flash. This does not affect the light quality (no walls or ceiling to bounce off of) but makes both lights pretty omnidirectional. It helps the on-camera flash put out a signal that the off-camera flash can easily see. At this working distance, I got a 1.000 batting average that way -- no misfires at all.
It does force your flash to put out more of it's power to compensate for the light being eaten by the dome. That will shorten the range in which you can work and/or increase recycle time. But it is offset by the fact that this flash is firing at two and a third stops under TTL, which pretty much negates dome-induced problems.
The key light has a dome and a 1/8 CTO get to warm things up a bit. This is a standard gel for my key light. And the dome means I do not have to concentrate on having good aim with my hand-held key. It lights in all directions.
Pop-up flashes work great as fill for this look, as you can see here, but you'll need to work pretty close to your subject. Also, you'll wanna lose the lens shade as it will throw a shadow from the pop-up (which is so close to the lens axis.) But honestly, if you can get away with a pop-up, the fact that the axis is closer makes it work better for this kind of on-axis fill.
In Nikon-CLS speak, my on-camera flash is the master flash and the handheld flash is the remote. They are both set to fire at TTL setting, with the on-camera fill dialed down 2 1/3 stops. Hopefully, people with other camera brands will interpolate these settings in the comments and post a translation. I no speak de Canon.
Recommended by Lazy Photographers Everywhere
If all of this sounds like a lot of work, it's not. Start at a 250th to get a friendly aperture, dial in the aperture that gives you the best saturated-looking scene. Set your key light at TTL and your on-camera flash at -2 to -3 stops under TTL for this look.
These setting are not set in stone, either. Play around. You can go for a natural look or really amp it. Keep your key light close to straight TTL for some level of "visual anchor" if you want to get weird with it. Drop the ambient a little more. Amp the fill a little more. Better to work against the ambient, too. That is to say, shoot into the light.
You'll get a wide variety of looks, and each will be suitable for different situations. But the important thing is the light-against-light control. And even more so, the ability to light three dimensionally on the run without stands, time or worry.
If you are already using this quickie two-flash technique please hit us in the comments on how you are doing it, and what you are shooting with it.
New to Strobist? Start here | Or jump right to Lighting 101
Connect w/Strobist readers via: Words | Photos
Got a question? Hit me on Twitter: @Strobist
Next live event: GPP PopUP Berlin (Oct. 29-30)