All digital cameras now include built-in flash; makes photography flash as easy as normal shooting. And the result is natural looking photography flash photos. All the worries for newcomer’s photographer in using photography flash to produce good photos are now gone in this digital camera era. All takes time calculation in using photography flash has become the past; fill-flash for ‘daylight’ is as easy as pressing a shutter bottom.

Today photography flash has very useful characteristic, it has a very short duration as fast as 1/1,000 second. So it benefits to capture fast moving objects; a speed that bare eyes cannot capture it.

Photography Flash can be used by ignoring the surrounding lights but can also be used together as an addition light. By combining both flash light and surrounding artificial light correctly can produce a superb quality photograph. Photography Flash can freeze the moves; combined with long exposures, can produce a full energy and dynamic photographs. This modern photography flash controlling can ease photographers working out this kind of balance.

Understanding Photography Flash

Photography Flash is a very useful device in supporting the photographers to produce photography works in a situation where the intensity of light is small enough to illuminate the photography objects. Even in the outdoors photography where the amount of light is abundant; photography flash can be used as fill-in flash to reduce the harsh of shadow at daytime. Photography Flash can produce an abundant light intensity that is as bright as the light at daytime as well as its color temperature. With this artificial flash light; you can produce the natural color from the objects.

Photography Flash commonly has duration as fast as 1/1,000 second; a fast duration that can freeze the fast moving objects. With this fast speed; the shutter speed setting in your camera doesn’t have much effect on the photo exposure. The exposure is controlled by the aperture of the lenses.

Guide Number (GN)

When the object distance is longer; the photography flash intensity is reduced. The stronger the intensity of the flash light the better and the distance reach is longer too. You can play with the Guide Number (GN) to determine the exposure relating to aperture setting; because the shutter speed doesn’t have much effect to the exposure. The guide number is often included in the model number of a photography flash, but not always. For example the flash has GN=40 at ISO speed 100; if your object is 10 meters away from the flash your aperture would be 40/10 = 4.

This formula can be described more clearly by understanding the diagram on the picture below. GN is the number supplied by the photography flash model for certain ISO setting.

Aperture = GN/L (L is the distance between the flash and the object)

Correlation between GN and Distance

For example the GN is 40 with ISO 100, if the distance between the photography flash and the object is 10 meters; you can calculate the aperture to use is GN/L = 40/10 equal to 4. But remember when you don’t apply the photography flash direct to the object but bounced to the reflector you need to calculate the distance through the reflector; l distance = L1+L2.

The other thing that you need to consider is the ISO; doubling ISO will close aperture 1 stop – and vice versa. For instance, if you were using 200 ISO speed and your f-stop in this instance is f5.6; when you double the ISO to 400 then you need to have the aperture 1 stop more; that is f8. Remember to use the aperture chart below as guideline.

Understanding these principles will enable you to make fairly accurate photography flash exposure settings. They also enable you to understand ambient/ flash exposure relationships. This knowledge is also handy for studio flash exposure if you don’t happen to have a photography flash meter but do know the guide number of your flash or studio flash head.

Flash Synch

In a camera, flash synchronization is defined as the firing of a photography flash coinciding with the shutter admitting light to photographic film or electronic image sensor. It is often shortened to flash sync or flash synch. In mechanical cameras, the synchronization mechanism usually consists of an electrical contact within the shutter mechanism. In electronic digital cameras, the mechanism is usually a programmable electronic timing circuit, which may take input from a mechanical shutter contact in some cameras, or hot shoe bracket.

M, F, FP, and X sync

Cameras are designed for use with photography flash bulbs generally had one or more of M (medium) sync, F (fast) sync, or FP (focal plane) sync, designed for use with corresponding bulb types. These sync modes close the contacts a few milliseconds before the shutter is open, to put the main pulse of light at the best time relative to the shutter opening. FP sync was designed for use with FP (flat-peak) flash bulbs which were designed for use with focal-plane shutters. Most standard flash bulbs used M sync.

The Nikon F offered FP, M, and ME bulb synchronizations, in addition to the X sync.

X (xenon) sync is a mode designed for use with electronic photography flash. In this mode, the timing of the contacts coincides exactly with the full opening of the shutter, since xenon flashes respond almost instantly.

Due to their construction, focal plane shutters as used on most SLRs will only allow xenon flash units to be used at shutter speeds slow enough that the entire shutter is open at once, typically at shutter speeds of 1/60 or slower, but some modern cameras may have an X-sync speed as high as 1/500 (e.g. Nikon D70). Electronic shutters used in some digital cameras do not have this limitation and may allow a very high X-sync speed.

Leaf shutters, which are generally much smaller and situated within the lens housing, can move much faster than focal plane shutters and allow flash sync across all shutter speeds (up to 1/1000 with a Rollei PQS lens).

Higher sync speeds are useful as they enable the brightness of the background to be controlled while maintaining normal flash exposure in the foreground, for example with a back-lit subject. See also photography background issues for camera exposure.

Today, certain modern xenon flash units have the ability to produce a longer-duration photography flash to permit X-synchronization at shorter shutter speeds. Instead of delivering one burst of light, the units deliver several smaller bursts a time interval as short at 1/125 of a second. This allows light to be delivered to the entire area of the film or image sensor even though the shutter is never fully open at any moment. The downside is that the flash is of less effective intensity since the individual bursts are lower powered than the normal capability of the flash unit. Only certain camera and flash combinations support this feature, and the camera-flash pairings are almost exclusively from the same manufacturer, the first being the Olympus OM-4 with the F280 flashgun. Off-camera flash units with this feature are currently very rare.

Rear-curtain sync

Some modern electronic cameras include the ability to fire the photography flash just before the closing of the shutter, so that moving objects will show a streak where they came from and a sharp image where they were at the end of the exposure, useful for moving objects to convey a sense of speed. This mode is called either rear-curtain sync or 2nd-curtain sync.

See also:

• Photography lighting techniques
• Digital SLR lenses – the terminologies
• Night photography
• Digital photography software – do you need this?
• Photography Coloring techniques