Take your first steps in flash photography
Trying to get a good flash exposure can appear complicated and best left to the pros. But everyone has to start somewhere – and it’s not as hard as it seems…
It’s somewhat ironic that, as a lighting technique, flash can leave many photographers shooting the dark. The world of flash photography can be a confusing and disorientating place when you’re just starting out. With a new set of initialisms to wrap your head around (TTL, HSS,
GN…) and the challenge of negotiating two exposures for every shot (one for the background and one for the flash-lit subject), it’s no wonder that a lot of people would rather stick with natural light, or reach for an LED panel instead.
But flash can be a wonderful creative tool. While a pop-up flash unit is limited in terms of position and power, a flashgun allows you to position the light so that it strikes the light from a more interesting angle, as well as experiment with a raft of light modifiers and coloured gels. LED panels don’t offer the same level of versatility or the raw power of flash.
Flash lighting isn’t just for shooting indoors or lighting up the night either, as it can help solve tricky exposures in daylight, too. If your flash unit is close enough and powerful enough, you’ll be able to open up ugly shadows in portraits and even overpower the sun to turn day into night.
One of the first decisions to make when you’re taking a photo with flash is whether you’re going to work with the flash unit set to TTL mode or Manual mode. TTL (Through The Lens) is an automated form of flash exposure, in
which the camera does most of the heavy lifting for you. Before making the main flash exposure, your digital camera fires a brief pulse of flash. This pre-flash is reflected by the subject back through the lens, where the camera measures the brightness of the flash and the ambient light before setting the intensity of the flash exposure for the photo. This all happens so quickly that most of the time the pre-flash is imperceptible.
The more advanced your camera is, the more precise the TTL flash metering system tends to be. As well as taking any ambient light into account in order to refine the flash exposure, the TTL system can use the camera’s AF points to work our where the subject is in the picture and, if the lens transmits distance information, how far away it is, too. It may also use the camera’s face detection system to prioritise the flash output for people in the picture.
If TTL can automatically work out a tricky flash exposure in the blink of an eye, why would you ever need to use a Manual flash exposure?
Well, for one thing, Manual gives you a predictable and consistent blast of light. If the subject is in front of a white background for one shot, and then a black background for the next shot, that won’t affect
If TTL can work out a tricky exposure in the blink of an eye, why the need for Manual?
a Manual flash exposure. Once you’ve dialled in the power level that you want to use, the flash unit will output that from one shot to the next – as long as it’s had time to recycle between shots, that is. The higher the power level, the fewer shots that you’ll be able to take in quick succession. Higher power settings also drain the batteries faster. However, if you turn down the flash power and move the flash unit closer to the subject, you’ll be able to achieve the same level of flash exposure that you get by turning the flash power up and positioning the flash unit further away. Lower flash power also has the advantage of enabling you to shoot more rapidly as well as preserving battery life.
When you’re using flash in the dark, then you only really have one exposure to worry about – that of the flash. When there is ambient light present, though, you’ll need to factor that in if you want to preserve some of the scene’s atmosphere. Using flash in daylight compounds the problem. You can of course leave it up to the camera to work out the exposure and the balance of the flash to ambient light, but if you have the time then it’s worth trying some manual adjustments to see if you can improve things. It’s easiest to treat the ambient and flash exposures as separate elements. First, without the flash switched on, set an exposure for the background. Setting the camera to Manual exposure gives
Lower flash power has the advantage of enabling you to shoot more rapidly, as well as preserve battery life
To eliminate hard shadows, take a flashgun off camera and use a softbox to diffuse the light
you the most control. You won’t be able to set a shutter speed faster than the flash sync speed, so set that first. Then adjust the aperture and ISO to give you the correct exposure. Now switch on the flash and set it to TTL. Take a test shot and use flash exposure compensation to fine-tune the brightness of the subject. You may prefer to work in Aperture Priority or Shutter Priority modes instead of Manual, but you might need to use exposure compensation to change the background brightness, followed by flash exposure compensation to adjust the flash brightness.
Of course, even after making adjustments to the flash brightness to make it blend in, it can still leave you with an obviously ‘flashed’ shot. To eliminate the hard shadows and ‘rabbit in the headlights’ look, take the flashgun off the camera, position it closer to the subject and use a softbox, umbrella or diffusion material to soften and spread the light. Even if you’re working with a naked flashgun, you can achieve a more flattering quality of light by bouncing it off a nearby wall or ceiling – as long as they’re not painted in a strong colour, otherwise you’ll end up with a colour cast on the subject!