using flash in digital photography
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DESCRIPTIONUsing Flash in digital photography, on camera bounce flash, video light, off camera flash, strobist flash,
The use of Flash in Photography
By Chris Timothy Image by Patrick Hoelck
The use of Flash in Photography 1. Introduction – Purpose and considerations 2. On Camera Bounce Flash 3. Strobist Flash 4. Video Lighting
Using Flash is key to controlling and manipulating light when available light is not the appropriate for the shot you hope to capture. Flash gets given a bad name by photographers using inbuilt factory camera flash. You have no control over the direction of the that type of flash. It can only come from one angle and height and usually hits the subject square on. The visual effect looks flat and lacks dimension and interaction between highlights and shadows. As photographers we’re always looking for perfect light and yet, the quality of available light isn’t always ideal. But if you use flash wisely, you are able to enhance or over-ride the available light in a location you wish to shoot in. With careful and considered use of flash, you are more in control of light, and hence the way your photos will look – than if you just accept the ambient light. the existing ambient light.
Introduction- Purpose Having the flash come from a different direction to that of the camera adds real depth and interaction of highlights and lows lights thus a nicer contrast. Flash can delete an unwanted light environment and add mood, emotion and connotations to your work. Here Patrick Hoelck’s Flash has added a nice gradient between the highlights and the shadows and also a natural vignette on the background. In addition to this it also acts as a key light to the secondary light, the window. It solves the problem of silhouetting. Flash can interact with as well as concur natural light.
Directional Flash by Patrick Hoelck
In built straight on Flash
Introduction – Considerations –Camera Tech/Settings To use Flash to its potential you have to consider your camera settings to ensure you correctly expose. There is no specific equation to ensure you do this correctly. However you do need to analyse the lighting situation that you are in and consider what effect the flash will have on it and ensure you leave room for it in your settings. For example deliberately under exposing to leave room for the flash to enter the shot.
1/160 @ f3.2 @ 800 ISO 1/160 @ f3.2 @ 800 ISO with flash Without flash With Flash
In digital SLR photography it’s important to understand what the light meter is and what it does before discussing how to use the camera’s built-in meter to set and manipulate exposure and in this case use it to helps allow for flash. The built-in light meter found in your digital SLR camera measures the amount of light being reflected off objects through the lens and into the camera. This measurement is then used by the camera’s computer to determine what it believes to be the best exposure for the scene, with that exposure being the proper combination of shutter speed and aperture and ISO.
Considerations. Exposure. Using the Light Meter
Here is a DSLR in built, on screen light meter. It is measured in stops. The image of the light meter says your exposure settings are correct. A -1 = under exposed,+1 = over exposed.
When we use Flash there is a danger we will wash out detail in anything which is already bright/reflective. For example a white dress or the sky. The screen on DSLR cameras are relatively small and it is difficult to check if a small areas has lost detail or is bleached out. You could use digital zoom on play mode to check. However this is time consuming. Another way to check is to use the histogram to analyse your exposure results.
Using the Histogram
A Histogram covers the Dynamic Range of color/tone from black to mid tones to white. Dynamic range in photography describes the ratio between the maximum and minimum measurable light intensities.
Using the Histogram
As long as the data in your graph finishes before the edge of the graph you are ok. If the data falls off the graph you have either over or under exposed.
Using the Histogram
Using the Histogram Under or over exposed?
So, when shooting with flash always check you histogram graph to ensure your shot is not under or over exposed. If you don’t you will probably loose detail in the high lights or shadows.
Using the Histogram
The Catch Light To learn how to use Flash it is always useful to analyse other peoples flash work. There is a really helpful clue to analysing where they have positioned or bounced their flash and it is called a Catch light. A catch light is a small white circle in the subjects eye which tells us where the flash was positioned in the shot.
Dean Freeman – Celebrity Portraits The Catch Light
On camera bounce
Image by Tom Munro
On camera bounce flash On camera bounce flash is a way of controlling your light. It turns being “on location” into a studio. The techniques requires the photographer to fire the flash at/on somewhere which reflects. You fire the flash where you would like a studio light positioned. Window
Firing the flash
It is important when using this technique you block any flash from hiDng your subject directly. You do this with various pieces of equipment but you could use a black piece of foam or even your hand. This technique allowed the photographer to bounce the flash to his leJ creaKng soJer light than a direct flash. The direcKon of the flash is well composed as the subjects take on a higher saturaKon than that of the locaKon.
Blocking Direct Flash
Here the Photographer has used the 70-‐200mm lens, a f2.8 wide open aperture and then simply has to wait for the right expression. He is posiKoned so that there are defocused highlights in the background to help create separaKon. The flash is bounced off to the right into the large recepKon room. Result-‐ slight contrast, well lit shot.
camera settings: 1/80 @ f4 @ 1600 ISO; TTL bounce flash. The Flash is shot to the left, reflects back and makes a nice combination of tones, again nice interaction between the highlights and shadows. All the same is not aesthetically pleasing. What is TTL? TTL is a AUTO for flash, it stands for through the lens. It looks through the lens and judges the light that is entering the camera and powers the flash levels accordingly.
Still life and T.T.L
Considerations – White Balance White Balance is a difficulty when using on camera bounce Flash. This differs from using a Strobist Flash. Your white balance really depends on if the flash fires at the subject directly, then you could set your shite balance to flash, or if you bounce your flash off a wall, texture, roof, it will bring some of the hue/colour tone from that service so your white balance may need to change to match it. The images below show the orange tones that reflect from the location. Shooting on RAW will enable you to change the white balance after you have shot to correct, or you can more complexly cool the image in Photoshop or Lightroom to help gain the desired tones.
Daylight white balance
Image by Tom Munro
The catch light
Strobist means off camera flash. This method of flash photography allows you to position the flash where you would like it as it is totally free of your camera. A photographer usually uses a stand or assistant. Your flash acts as your studio light. In this technique you need to sync a flash gun/speed light with your camera. This then enables your flash to go off at the exact moment your camera takes a picture. There are some advantages and disadvantages of shooting Strobist rather than On camera bounce flash. For example the light will be much harsher in strobist because all the flash hits your subject. It is not diffused like bounce flash so therefore is hard more direct light rather than soft. This results in a high contrast image.
To conduct this technique expose your shot pre flash, one stop under to allow for when the flash enters the shot. The camera light meter will help you in this.
Strobist Flash using T.T.L
Position your subject and flash to gain the desired shadows. Here a soft box is used to diffuse the light. The light is being held with a Monopod rather than a stand on this occasion. You can filter flash to match the colour of the current light sources. Flash tends to be blue, cheap flash lights have more green Knts.
1/200 @F/2.5 @ 200 ISO 1/200 @F/2.5 @ 200 ISO with TTL flash
Tutorial for Strobist Flash http://www.youtube.com/user/CamCrunch?feature=watch
Here you can see a circular L.E.D video light on the Canon Flash gun under the flash.
Video Light In addition to using various speedlights and flashguns. Video lighing is another technique which can provide great effect. Using video light in a scenario where tungsten light is the dominant source of light, helps in achieving a more natural look. Video light is also a continuous light source, making immediate changes to the lighting intuitive – what you see is how it will appear. You need to judge each scenario to decide if to use On camera bounce flash, Strobist or Video lighting.
On camera bounce flash Off camera Video Flash
Video light allows for constant adjustment of the light. LED is usually day light colour. Its whiter than regular bulbs which tend to have the orange warm tungsten glow.
Our task; Shoot 3 portraits
Using; 1. On Camera Bounce Flash
2. Strobist Flash 3. Video Lighting
Your images should be perfectly exposed. Your cameras manual seDngs/tech, light meter, white balance and histogram should be consulted when shooKng. Your portraits can occur in an environment of your choice of whoever you wish. These techniques can be shot in day or night. To do this technique correctly your images should contain a smooth gradient and
combinaKon and interacKon of highlights and shadows.