Outdoor Flash - When To Use It (Or Not)

[Curtis N]

This is sort of a tutorial for the novice outdoor flasher and hopefully a catalyst for some discussion of the subject.

I'm talking about "run & gun" type shooting with a hotshoe flash when you're not planning on a lot of subject cooperation. The points here will apply whether you're a hired event shooter, grabbing candids at a public event or everyday family snapshots. This is not about formal portraits or off-camera flash.

And before you ask... no, you don't use a "diffuser" on your flash outdoors. They won't do you any good and they waste power. Direct flash is the only viable option.

One of the first decisions you need to make is whether or not to use High Speed Sync (FP Flash). This mode allows fast shutter speeds and therefore large apertures. It's a nifty tool for when you want to blur the background in bright conditions. But it is less efficient, cuts your range in half and leads to longer recycle times and shorter battery life. The decisions is yours, but be mindful of the limitations and keep an eye on your flash unit's distance scale.

I highly recommend using Manual exposure mode on your camera. It's important to take control of the camera and make deliberate decisions regarding exposure. If you don't use high speed sync then you'll want to set your shutter at X-sync speed and stop down the aperture to get the ambient exposure you want.

Now a word about Flash Exposure Compensation (FEC): The best FEC setting depends on the camera, your subject, and the reason you're using flash to begin with. I have used FEC settings from -2 to +2 outdoors. Don't let someone tell you where to set your FEC. It's just something that only experience can teach you.

So, let's go through some examples of situations where flash can be used to improve an outdoor shot.

#1 - Harsh shadows on a sunny day. Flash will reduce the contrast from sunlit to shaded part of an image. This improves faces dramatically. Properly implemented, you will get a natural looking image that still has hard-edged shadows from the sun but has decent exposure of shaded areas.




#2 - Backlit subject. Putting the sun behind your subject (if you're lucky enough to have the luxury) can make some real nice portraits with fill flash. The sun makes a nice hair light. This girl would be terribly underexposed without flash.




#3 - Shaded subject, sunny background. Without flash, you have the option of underexposing your subject or blowing out the background completely. Flash allows you to meter for the background and properly expose your subject.




#4 - Light up the face under the hat. Just be sure to rotate the camera to vertical orientation or you'll make a nasty shadow under the hat brim. 'Nuff said.




#5 - "Just because." Even on an overcast day, a bit of flash will make your subject "pop" by exposing her just a bit brighter and providing catchlights.

[Curtis N]

Now the next step in the learning process is learning to recognize good light when you have it, and leave well enough alone. When you're blessed with open shade or a huge doorway that becomes "God's softbox," for heaven's sake, turn off the flash so you don't ruin the shot. Here are a few taken without flash.










Now I want to point out the most significant downside to using flash outdoors. It will create shadows on your subject or behind your subject if the background is close, and sometimes it's worse when you use the camera in vertical orientation. Because of this, flash can do more harm than good if you're not careful. Here's a shot where I wish I had turned the flash off.




For this shot, I rotated the camera backwards (shutter button down) to put the flash on the right side of the camera. Rotating it the other way would have made a nasty shadow by her hat brim. If you look carefully, you can see the shadow on the left side of her mug.




Deciding whether or not to use flash isn't always easy. Here's a shot where I had nice natural light so I turned it off (partly to avoid catching her attention). But I'm left with no catchlights so her eyes don't have that sparkle that would really add life to the image. Just a tiny bit of flash would have done the trick.




So there you have it. The outdoor "run & gun" hotshoe flash basics. Remember, you have two exposures to manage - an ambient light exposure and a flash exposure. Getting them both right is the hardest part.

[mikeassk]

Nice write up! Great tips.
I love the reaction I get from on lookers when I use the "upsidedown Flash" technique... Like " is that guy for real" haha.

[c2thew]

agreed. nice write up and great use of pictures to supplement your article. thanks

[Undispu7ed]

Nice write up

[watt100]

thx for tutorial

[dongnat]

Very practical and usefull pointers.
Thank you

[egordon99]

Great tutorial....I find the biggest improvement my photography has seen has been by me learning to "read the light" over the last year or so.

I wish I had concentrated on this more when I started out instead of going nuts buying lenses

[sdipirro]

Curtis, this was an excellent description of the benefits and drawbacks of using flash outdoors, especially with the pictures to illustrate it. What would help me even more would be to understand your decision-making process for at least some of these photos as far as how you metered them and how you adjusted FEC for the different cases.

[Subfightersandman]

Originally Posted by sdipirro

Curtis, this was an excellent description of the benefits and drawbacks of using flash outdoors, especially with the pictures to illustrate it. What would help me even more would be to understand your decision-making process for at least some of these photos as far as how you metered them and how you adjusted FEC for the different cases.

Agreed, i am good a deciding when to use flash, i just suck at getting the metering right I usually wind taking 4 or 5 shots trying to get my flash power and exposure balanced.

[Jon Foster]

It's funny that you posted this now. I've been playing around with my fill flash a lot lately. I'm finding that leaving my flash at about -1 FEC gives me shots I'm pretty happy with. Most of the time. Some times I need to play around + or - a bit but shots are generally acceptable. I do a lot of running & gunning at renaissance festivals. I've also noticed that if I don't dial in any FEC a stofen on the flash works pretty well. It kills the catch light in the subjects eyes. That alone is worth using it to me. Most people never even realize I used a flash.

I'm also starting to play around with gels on my fill flash. The results are starting to look promising.

Jon.

[bobbyz]

Nice stuff. Thanks.

Now I need to go visit the renaissance fair

[dtfuzzy]

Thanks nice write up and a good study

[Curtis N]

Originally Posted by sdipirro

What would help me even more would be to understand your decision-making process...

I've thought about this for most of the day and realized that if I invited you into my brain, you'd just get lost in the mess.

Nevertheless, here's my attempt to walk you through my approach. Follow at your own risk.

Before you think about exposure, read the light and position yourself to take advantage of it. Sometimes you need to decide between the best background and the best lighting. The pumpkin field in #1 is no accident, but I knew the light would be harsh from that position. In the parade shot, I positioned myself on the east side of the street to get the sun behind the subjects, but the background would have been better from the other side. That was a deliberate decision I made before the parade even started. It takes some luck to get a great shot, but you'll be luckier if you think ahead.

1) I'm usually using a 70-200 lens for this stuff and nothing torques me off more than to have a great shot ruined by motion blur. But I stay away from HSS because that reduces range and I never know how far away the action will be. So I set my shutter at 1/250 and leave it there (If you have a 5D or Rebel series camera then it'll be 1/200). If you check the EXIF on the photos above, you'll find a variety of aperture and ISO settings but I'll bet almost all of them are at 1/250 shutter speed.

2) I always think about, then determine, my background (ambient) exposure first. If I'm in the sun, I'll start at "sunny 16" (which is basically f/10 at 1/250 shutter, or f/11 at 1/200). If you aren't using flash, you can get away with f/9 or f/8 in the sun at those shutter speeds. But the flash will add exposure to the highlights as well as the shadows so if you push the ambient exposure too far, you'll blow some highlights with flash.

3) If the whole composition is shaded, or if it's cloudy, then I open the aperture as far as I'm comfortable and then crank up the ISO as needed. In changing conditions I adjust ISO more than I adjust shutter speed or aperture. Shutter speed controls motion blur, aperture controls DOF, ISO controls exposure.

4) My 20D and my 1D Mk III behave differently in terms of FEC, so you have to take FEC recommendations with caution. But for fill flash I usually start with FEC at about 1 stop less than I would use with flash as the main light. So for example if you typically use +2/3 FEC for indoor bounced flash, start at -1/3 FEC for fill. But that's just a starting point.

5) For backlit subjects, the flash will need to provide most of the light so crank it up. If your subject is already well lit and you just want to add catchlights and a bit of pop, then crank it down. Remember, the E-TTL system has only your subject to meter on. That means differences in subject luminance will affect it more than when you're shooting indoors. White blouse? You'll need to crank up the FEC. Black shirt? crank it down.

There are no rules, there are only your goals and vision and balancing ambient and flash exposures to achieve them.

[verymagicalguy]

Originally Posted by mikeassk

Nice write up! Great tips.
I love the reaction I get from on lookers when I use the "upsidedown Flash" technique... Like " is that guy for real" haha.

Never thought about doing this, good tip. I'm sure it does look insane though haha.