Flash Photography
My first flash gun consisted of a battery holder with a folding reflector and a 6 inch cable to connect it to the camera’s flash nipple. And since cameras did not have either hot-shoes or any other mounting point for a flash gun, I had to buy a flash bracket to attach to the tripod bush or learn to shoot one-handed. Sound primitive? Surprisingly there are some advantages to this setup, as we will see later in the Intel. Oh! Almost forgot...we weren't working with flash-tubes or strobe, either. The battery holder accepted flash bulbs - one flash, throw it away, put in another; they were just fine magnesium wire in a plastic coated glass bulb, blue-tinted (for daylight film) or clear (for film balanced for tungsten lights). They came in different sizes and had different flash durations and brightness outputs for different situations, and only “professional” cameras could synchronise with all the different types. The height of sophistication was a slide-rule attached on the back to help you calculate the camera settings. Much later, semi-automatic flash guns with strobe tubes were introduced. On these it was enough to set the film ISO and transfer the setting it recommended to the camera’s aperture dial.
Flash photography is a good deal simpler now, and we take it for granted that a flash unit will be included in any camera we may buy - even throw-away ones! But beyond lighting a dark interior, what is a flash good for, what are its limitations, and how can they be overcome? This Intel is about getting the best out of the flash you’ve got, and choosing the best flash for the kind of photography you want to do.
Flash Photography - The camera may calculate the exposure now, but all the rules that governed flash in the “old days” still apply, and if you understand them, your photography will benefit. That doesn’t mean you can’t use the sophisticated through-the-lens flash metering system or other innovations you camera can provide, but knowing what is going on lets you get the best out of the system.
Taking Control - The typical situations where your camera will try to flash automatically are too dark for well-exposed photo at the ISO setting of your film or sensor. But your camera may also switch on flash if it calculates that you won’t be able to hold the camera steady at the shutter speed it has to set. Useful, but not foolproof.
The camera does not know what kind of picture you want to take; it does not know if the camera is in your hands or has been placed it on a tripod, or that you are using a monopod; it does not understand you want to capture the natural glow of sunlight on the walls, which will be completely destroyed by the brilliant wash of the flash. It doesn’t realise that the part of the picture you want to capture is out of range of the flash light, and it doesn’t know that harsh shadows will spoil the mood of your intended portrait.
The first thing you must do therefore, is learn how and when to turn off the flash; the second is how to modify the flash when it is on. For the sake of this Intel, we won’t be concerned with sophisticated, off-the-camera outfits with soft-boxes, snoots and baffles. If you have that sort of gear, you don’t need this sort of advice! Instead we will consider 3 sorts of flash and how to manage them, but first a note about flash modes.
Flash Modes - Just about every digital camera, and most film cameras give you some choices about how your flash works. Look for a button marked with a lightening flash to cycle through the options. If you can’t see it, look up “flash” in your manual. You should have choices like these: AUTO / AUTO+RED-EYE REDUCTION / ALWAYS FLASH/ ALWAYS FLASH+RED EYE REDUCTION / NIGHT PORTRAIT / ALWAYS OFF.
Your camera may not have them all or it may have even more options. The minimum you should expect is AUTO and ALWAYS OFF.
Auto - means that the flash will fire if the ambient light level is too low or
if the background is much brighter than the foreground (it tries to stop the subject being underexposed and turning into a silhouette)
Auto+ Red-eye Reduction - just like AUTO but before the flash picture is taken, one of 3 things happens: a beam of light like a small torch comes on for a few moments, or the flash fires once, or the flash fires a burst of short flashes. The idea is to shine enough light in the subject’s eyes to make the pupil contract enough to stop the main flash reflecting back into the camera lens and making them look like some sort of demon with glowing eyes. None of these work 100%, but they are pretty good. You need to warn the subject, or they can think the pictures has been taken when the first flash goes off, and stop smiling or move. You have to watch out for the same reason, and you also have to be careful not to put a finger over the little lens that focuses the torch beam on your subject if that system is used.
Always Flash - also known as forced flash means that the flash goes off whether the camera thinks it should or not. In dim light the camera calculates the right exposure to make the flash the main light, but in bright conditions, it exposes for the anmbient light and the flash just fill in the shadows.
Always Flash+Red-eye Reduction - both red-eye and flash always on.
Night Portrait - Technically this is “slow synch” flash. Used after dark, the shutter opens and the flash fires, but instead of closing, the shutter stays open for long enough to record the background. That allows you to get a picture of a person or object and also record the lights, fireworks etc. behind them. Just make sure neither the camera nor the foreground subject moves until the shutter closes!
Always Off - stops the flash operating, even in pitch black
Flash Units - We will consider just 3 types which we’ll call Window, Pop-up, and External. Window and Pop-up are built into the camera, while External units are usually purchased separately although a few come with the camera and have to be attached when you want to use them.
Window - are the simplest and most compact. Their advantage is size, but they are the least powerful and most likely to cause red-eye and harsh, ugly shadows; they are also the kind you tend to put your fingers over.
Pop-up flashes - may pop-up automatically when they are needed, or you might have to release them when needed (the camera will have a light or other signal to tell you when), If you don’t notice the signal, you might miss the shot, but there are plenty of advantages, too. More power, less red-eye and the chance to modify the intensity of the flash. In some cases it is also easier to modify the output using gels or diffusers, although this is really the province of external flash units.
External Flash Units - The most powerful and flexible option. They can sit on the camera attached via a “shoe” most of these little brackets are “Hot Shoes” with contacts to synchronise the flash with the shutter. If your camera doesn’t have a hot shoe, you can screw a simple flash bracket into the tripod bush and use your in-built flash to trigger the external unit (more of that later). Even better, you can move the flash off the camera and do away with red-eye and hard shadows altogether. You can even use more than one flash at a time!
Flash Opportunities and Basic Considerations - Flash is more than just a convenience when lights are low. You may want simply want to light a pet group of people for a portrait photo, but you may want to throw light into a room for an architectural photo, or you highlight a certain object in a lighted.
Some simple techniques
* Don’t fire your flash directly at a mirror or glass: the reflection (flare) will ruin the photo.
* A built in flash has a range of about 2 to 3 metres (6 to 10 feet), so be sure you are close enough. You will get a bit more range in a small, light-coloured room, much less outdoors where there is no wall or ceiling. You can also get more range by increasing your ISO. None of these is enough to get a shot at a sporting fixtures, a show or a concert, and the flash setting will spoil any chance of getting an “available light” picture. Turn it off and avoid upsetting the performers and other patrons!
* Flash falls off really fast (as the square of the distance - double the distance, 1/4 the light), so make sure your main subjects are all about the same distance away from the flash, or some will be right, some washed out and some too dark to see.
* Flash is useful on sunny day to lighten shadows on a subject’s face (“fill flash”) or shaded area in a landscape if they are close enough. Fill in flash is ideal for back-lit and side-lit situations. In a back-lit situation the subject is in their own shadow which creates a silhouette effect. Fine if that’s what you want, but if not, fill flash will balance the photo nicely.
b]More Advanced Ideas -
Bounce - Many photographers bounce the flash off a wall or ceiling to get a softer diffused kind of light. Many professionals use this method almost exclusively.It requires a flash that can be aimed toward the walls or ceilings, or a little bit of innovation: with a pop-up flash or an external unit that doesn’t have a bounce-head, it is simple to make a small reflector form white plastic or stiff white card to attach beneath the flash head, Angled up at about 30 to 45 degrees, it converts straight flash to bounce. The limitation is flash power.
Recall that the maximum range for most on-camera units is about 10 feet. From flash to ceiling and back to the subject may well be beyond this limit, and more light is lost as the reflecting ceiling or wall absorbs and then spreads the light.
More on Fill Flash - Outdoor scenes often contain a higher dynamic range (differnce between highlights and shadows) than a camera can handle. Deep shadows will often obscure your subject’s facial features. This is especially a problem when the subject is wearing a hat that shades their face. Flash fill adds light to “bring up” or fill those areas to reduce the shadows and reveal the facial detail. Generally it is desirable to retain some shadow, as it looks more natural and reveals texture giving the image a three-dimensional feel.
What’s the proper flash level for fill flash? Modern automatic flash is programmed to automatically reduce flash output in bright light settings. When and how much flash is automatically reduced is up to the camera. However, some cameras allow you to increase or decrease the flash output (check your manual). If not, you can use ordinary exposure compensation to achieve a similar result. If the results are too bright or too dull, add or subtract 1 stop or boost/reduce the flash output by a similar amount.
Exposure Compensation and Flash - Experiment with your flash in different situations to learn how your system adapts; in which the flash looks too hot (over exposed) or cold (underexposed). you will need to help the system by adding flash exposure compensation. If you can control the flash output, set the flash to expose the subject 1 or 1 1/2 stops below the ambient light level. This lightens and keeps detail in shadowed areas that would otherwise go black in your photo.
On some flash systems--Canon is one--flash exposure compensation is added to (subtracted from) the flash exposure compensation automatically introduced by the system’s daylight flash-fill program. You can cancel the automatic preprogrammed reduction via one of the custom functions. Read your manual to see if this applies to your system.
Dramatic Backgrounds - Macro and portraits really stand out from a completely black background. This is very easy to produce using flash. Because the light falls of so quickly, you need do nothing more than ensure that the general lighting conditions are fairly low and that there is nothing close to the subject to reflect light back from the flash. Careful use of this effect can create very dramatic photos.
Alternatively, overexposing the background can produce exciting photos with back lit subjects. If the zoom level of your auxiliary flash is manually adjustable, set it wider than the lens you are using. When using a 100mm lens, set the flash zoom to 28mm, for example. Be aware that this will reduce your flash’s effective range.
Try bouncing the flash off a reflector. A white or silver reflector yields strong, directional light while the results obtained by bouncing flash off a warm tone reflector are softer and more subtle. You can buy reflectors, but they are simple to make from a piece of card or aluminium foil. Folding heat reflectors designed to keep cars cool work fine, too.
Multiple Flash - There is no need to limit yourself to just one flash, and even the simplest window-type system can control multiple flash guns. You can buy very inexpensive flash units ($20 and less) that feature a photoelectric cell which triggers the flash when your on -camera flash fires. Some cameras fire a pre-flash as a focusing aid a moment before the “real” flash goes off. If you are getting secondary flashes or a larger auxiliary flash, just make sure they can be adjusted to allow for the pre-flash.
Set up multiple flash units: start out with one aimed at your primary subject, another at the background, and move the background light until you get the effect you want. Try the remote flash with a reflector for studio style lighting on a shoestring!
About Synch Speed - Every camera will have a maximum shutter speed at which you can take flash pictures. Modern TTL cameras usually sync speeds at speeds of 1/250 or higher, while simpler cameras may synch up to 1/60 of 1/125 sec. In low light conditions, the actual duration of the flash determines the exposure, and this is typically 1/1000 sec or faster.
Restricting your flash shooting to the sync shutter speed severely limits your creative options. Using slower shutter speeds may allow a smaller aperture for more depth of field or let you include areas of the picture outside the range of the flash gun with more light than the closer areas, often useful in shooting interiors. It gives you the opportunity for creative blur or light trails behind a properly exposed foreground. If you cannot directly control the shutter speed with flash enabled, try setting Night Portrait Mode. Use a tripod.
Increase Dynamic Range - Use flash to illuminate a darkened foreground element that is within flash range – a person, a cluster of flowers, the inside of a room or doorway and still get the outer or more distant scene (like the sunrise) properly exposed. This works even better if you can remove the flash from the hot shoe and attach it to your camera via a TTL flash extension cord and place them in the most strategic position.
Colouring the Scene - Flash units produce light the same “colour temperature” as daylight (actually, sun+skylight on a cloudless day about noon in the temperate zone!) When shooting in the magic warm light of morning or evening, a flash illuminated subject often looks out of place. Many flash guns come supplied with coloured filters to modify this light and you can obtain gel filters which can be taped over any flash head, to alter the colour of your flash’s light. Gel filter packs by manufacturers like Rosco (www.rosco.com) fit most flash heads. You can experiment with any material and colour you like to get more natural or quite bizarre effects.
Second Curtain Synch - The shutters on SLR cameras don’t open and close; they run a strip of light along the sensor/film. You may be able to choose whether the flash goes off at the beginning of the exposure (‘first curtain’) or at the end of the exposure (‘second curtain’). Second curtain flash generally gives more natural looking results with moving objects. Shoot a moving car with ‘first curtain’ and it will appear with a ghost preceding it. Interesting, but unnatural. The same car shot with ‘second curtain’ flash will gain a sense of movement; the ghost like shadow will trace the path it moved during the exposure rather like a "speed blur" - nice.
{b]Off Camera Flash - Nothing improves flash photos more than getting your flash unit out of the hot shoe. An flash extension cable or wireless flash unit (some cameras have this built in) lets you achieve this easily, but juggling a flash, even with a tripod mounted camera gets cumbersome. A flash bracket frees your hand so you can better concentrate on your photography.
A flash bracket also dramatically reduces the likelihood of flash shadows and red eye when Many macro flash brackets (are also available to let you get your flash illuminate subjects that would otherwise be impossible to light with flash.
Painting with Flash - Here’s a fascinating technique for illuminating large areas at night, with only a single ordinary flash unit. "Painting with Light" requires a flash gun that you can take off the camera, and a way of keeping the camera lens open for a very long exposure, which means this is a dark night technique. It is surprisingly simple.
You don’t need through the lens flash metering for this trick. Set the camera up on a tripod, with the main subjects of interest in the centre of the frame Make sure the camera is focused on the nearest subject of interest; a flashlight is helpful or this, and manual focus is better than auto.
Cover the lens with a dark cloth and lock the shutter open; there are several ways to do this - a locking cable release with the camera on the "bulb" setting ('B' on the camera's shutter speed dial), or, if it's an older or professional camera, placing it on the "T" setting (for time exposure); if the camera has no way to attach a cable release, take a piece of paper or fabric, fold it into a wad around a strong rubber band and use the combination to hold down your shutter button.
Now comes the fun part. Turn on the flash gun and walk off into the picture (almost forgot: wear dark clothes!). Try not to walk between lights and the camera, and move around the scene, setting off the flash as you go, paint in the important parts of the scene. Start at the camera, hold the flash up high, and fire the flash 4 or 5 times, directly at the scene by pressing the “test” button. Walk out 17 or 18 feet from the midline of your scene on either side, and flash 5 times again, pointing the flash towards the midline. Take 5 steps down the "sideline", keeping about the same distance out at all times. Every 5 steps, hold the flash up above your head and fire it 5 times in a slightly downward angle. Remember to make sure you don’t get between the flash and the camera and that the flash head is always away from the camera. Do the same on the other side
You will need to experiment a bit with the number of times you flash at each location, because no 2 flash units are the same, and for an even more spectacular “painting” try this with a ruined building, firing the flash from inside!
It is a great idea to have a friend who can cover the lens between flashes and also protect the camera while you are off in the dark!
End Bit - Flash is a very simple tool but even simple tools can be put to amazing uses. These ideas are just the starting points for your own flash explorations. Try a few new approaches and see what you can achieve!
