Sunday, October 24, 2010

14 professional flash tips

Here’s a concise list of 14 tips for using flash to enhance your images. I jotted down a few notes based on my experience and the result is the ‘idea storm’ below.

Seems obvious but it has to be said: the first thing to do is to establish your point-of-view, where are you going to put your camera; then look at the available light. If the natural light is good, don’t mess with it. If you do decide to use flash then be careful not to ‘over light’ your subjects and make them look unreal and garish (unless unreal is what you’re trying to communicate of course).

Always remember flash light is balanced to be the same as bright daylight. You can alter the colour of the light when using your flash by applying different coloured gels over the flash head. Gels come in two basic varieties. Those used to correct colour balance (matching flash to tungsten lighting, TL lighting etc) and those used for special effects.

I’ll try to keep this as concise as possible. If you have any questions just get in touch and I’ll do my best to answer.

1. White balance

Control the colour in your image by using your white balance settings. For example, if you set your camera to tungsten WB, then the overall tone when using flash will be blue. But here’s the thing. The brightest parts of the image will be more neutral because the brightness of the flash will ‘wash away’ the blueness. Adding other flashes gelled with an orange tungsten correction filter (CTO) or tungsten lights you can add warm accents back into the overall scene. One of the fundamentals of colour photography is playing with the balance between warm and cool colours (it’s key to controlling the mood and psychological impact of the image).

2. Flattering portrait light

An age old trick to produce flattering light is to use a ‘clam-shell’ setup. The top flash, diffused and softened is set up to be 1-2 stops brighter than the fill flash (also diffused) which is aimed upwards from below your subjects face. The camera sits at the narrow end of the clam-shell (cam< mod) and the model is at the mouth of the clam-shell.

3. Don’t light your subject

You can use off-camera flash to light the surroundings rather than the subject. This can help isolate the subject and make it/him/her stand out. You don’t always have to light the subject. Think about it. Every image has a foreground, middle-ground and background. Think about using your flash to separate these zones in the image.

4. Rim light

You can create a dramatic effect by using your flash to rim light your subject. This will separate them from the background. Place your flash to one side and behind the subject. If you have two flashes you can place them on either side of the subject. This setup is often called ‘hatchet’ lighting. Be careful of lens flare when you try this.

5. Touch of light

When using your main flash off-camera, don’t forget that the little pop up flash on your camera can be used to add an extra touch of pleasing light, for example to put a sparkle in your subject’s eyes, and it helps to separate the subject from the background. Don’t overdo it or you’ll destroy the effect of your main off-camera flash. The touch of extra flash should usually be -1 to -2 EV of the ‘correct’ exposure.

6. Zoom your flash

When you use a cable or dedicated wireless control on your off-camera flash, modern technology is clever enough to enable the lens and flash ‘speak’ to each other. The flash knows that it should zoom the flash to match the lens on your camera.This is not always something you want. Because sometimes you need to take control and use the zoom on your flash to change the quality of the light. A 200mm zoom setting on your flash will produced a more concentrated and harsher pin point of light, while a 24mm setting will disperse the light across the frame. When is this important? One example: if you’re imitating the setting sun with your small flash you’ll want to get the flash as far away from your subject as possible and zoom it to 200mm; and also gel it with an orange (CTO) filter. This will imitate the bright point light of the setting sun.

7. Balancing light in offices and non-domestic buildings

Fluorescent lighting is a nightmare. It’s greenish and when you have to use flash you need to reconcile the two different WB requirements. The easiest way is to gel your flash with the appropriate green colour correction filter and bounce the flash off of the ceiling, while using a white card on the flash or another commercial light shaper to chuck light forward at the same time. The Canon 580 EXII flash has a built in white card to throw light forward. You can also use a number of commercial products which aim to bounce light up and forward, approximately in a 80:20 ratio.

8. Intense colour using flash

If you’re after theatrical effects and you want to try using coloured gels on your flash, you may find the results disappointing because the brightness of your flash will wash the colour out. To get those intense, reds, blues and greens, you need to dial down the power on your flash. You can also increase the intensity of the colour by doubling-up with the same colour gel. Make sure that the gel seals the flash because any white light leaking out will ‘bleed’ the colour.

9. Lighting a group of people

Using one small flash for a groupshot is a challenge. If you use your flash at the height of the camera from the front, inevitably the foreground people are brighter than the background people. The best way to deal with this is to get your flash up high and aim it toward the back of the group, and then diffuse it (shoot through material eg an umbrella, or bounce of a reflector etc). The light will wash over the foreground people and evenly light the group. If you can use more than one off-camera flash, all the better. Aim for the the back of the group and to create the biggest swathe of light you can get.

10. Controlling ambient light

Using flash is not just about pointing your flash at the subject. You need to control the ambient light as well. Think about blocking or diffusing ambient light to reduce it’s effect on your subject. This then gives you a fighting chance to dominate your subject with your flash lighting.

11. Bouncing light

When you’re in an environment look at what the natural sources of light are and see whether you can enhance them. Place your flash outside a window (to imitate daylight), bounce it off a mirror or a white wall, through a doorway, off a reflector, off a sheet/reflector on the floor. In any environment you have to look at all the light sources. Light is bouncing around from everything. You can also put your flash inside or next to a light fitting to imitate light from it. Always remember there should be a logical reason for light to be coming from something or the viewer will have trouble making sense of it.

12. Controlling the light from your flash

There are hundreds of diffusers, reflectors and devices to alter the light coming from your flash. When you use your flash to shoot through an umbrella, think about using things to block and shape the light (the black covering on many shoot through/reflect umbrellas), gaffer tape, a jacket, your hands etc. Make sure the right amount of light is hitting your subject where it counts. Each subject is different. The key to subtle lighting is to shape your light by using masks (gobos, flags, cutters, cookies or whatever you want to call the things that you put between your light source and your subject).

13. Using camera controls

When using flash think about using your camera controls to produce interesting effects. Use different white balance settings (or filters on your lens), and filters on your flash and think about ways to combine both to enhance the overall colours of your subject. Use your shutter speed to vary the effect of ambient light in your image. Try second curtain flash. Experimentation is the key. You’ll build up your own bank of knowledge with everything you try.

14. Using flash controls

Your flash controls are: power settings (+/- EV values); distance from subject; angle of light; diffusion; flash zoom setting; bounce angle; ambient light balance; iTTL/eTTL etc; aperture setting; manual override; high speed sync; strobe/multi-flash etc to name some of the main ones. Get your flash off-camera for more natural results and to really control your overall lighting.

I hope these tips prove useful. Feel free to share yours too in the comment form below. I’m always keen to learn more.

You may also be interested in these blog articles which explore elements hinted at above in more depth:

Till soon,
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