Flash Photography Three types of flashes • On camera flash, or pop up flash. • Not very useful because the light is small, not very powerful, and only points forward. Three types of flashes • Speedlight (also known as hot shoe flash or flash gun). Very cheap and a lot better than pop up. • More powerful and larger than the built in flash. Can point in different directions and be either attached or taken off the camera. • More settings than a pop up flash. Three types of flashes • Strobes, or studio flash. • Much more powerful and versatile than Speedlights, but very expensive, much larger, and more difficult to use. • Can be flashed or continuous. When to use flash • Inside or in darker light when you want to increase your shutter speed, but not your ISO. When to use flash • Outside with harsh light. Called “fill flash”, this can be used to fill in shadows caused by hard light (such as the sun at noon). Or can be used when someone is in the shade during the day. When to use flash • When a creative effect is wanted, such as hard shadows or a more dramatic photo. Problems with flash • Direct flash can look too harsh if set too powerful. When set properly though, the result can be pleasant. Problems with flash • Flash can reflect off of shiny or smooth objects Problems with flash • Direct flash can create strong shadows. Problems with flash • On-camera and direct flash can cause red-eye (sometimes unavoidable, but can be corrected in Lightroom or Photoshop). • Your camera may also have a red eye reduction setting, which fires a pre flash and prevents red eye. Using Flash How a flash works • When the shutter button is pressed with the flash turned on… – The shutter rises – The flash fires – The shutter closes • Essentially photos using flash are two exposures, one from the ambient light, and one from the flash. What affects flash? • Aperture-Affects the strength of the flash and the ambient light • ISO-Affects the strength and distance the flash is effective and ambient light • Settings for the actual flash (output). • Shutter speed-only affects the ambient light. It has no effect on the flash (although with flash, the maximum shutter speed is set, usually 1/250 sec for higher end cameras). Shutter Speed Notice how the background goes from darker to lighter as the shutter speed decreases, but the subject with the flash pointed at it stays almost the same. Shutter speed does not affect flash. ISO 100 f/5 1/250 1/160 1/100 1/60 1/40 1/25 Flash falloff • The further away something is, the less effective the flash is. • Every time you double the distance, you need 4x more flash power. • For example, if someone is 1 m away, and the next person is 2m away, the first person will be 4x brighter from the flash. • ISO can increase the distance up to a point, but also affects noise and ambient exposure. 1m 2m Flash Sync • Most cameras limit the maximum shutter speed to 1/200 sec when using flash (professional cameras can go up to 1/250-1/500). Some cameras also set the minimum to 1/60 sec. • Use ISO and aperture to compensate. • “High speed sync” and “slow speed sync” can be used sometimes to shoot with higher or lower shutter speeds. This is usually only available if using a Speedlight that is the same brand as your camera. Shutter speed too fast (1/400) Caused because the shutter opens but closes before the flash is done firing. Taking a picture • For simple automatic use, turn on the flash and set the camera to Aperture Priority, Shutter Priority, or Program mode. • Turn on the camera’s flash and shoot. • If using a Speedlight, set the mode to TTL (or ETTL/ITTL, depending on the model). Manual Control Flash Exposure Compensation, Front and Rear Curtain Sync, High and Slow Speed Sync Manual Control • You can adjust the Flash Exposure Compensation (FEC) on the camera or on the Speedlight (if using one). Works like Exposure Compensation (EC) on the camera, but adjusts the output of the flash. • EC adjust ambient light and FEC adjust the power of the flash. Experiment with different combinations of both. • Most newer or high end flashes will also adjust the distance (the flash “zooms”) depending on the focal length of the lens used. On some low end and older models, this can be done manually. EC and FEC • Try underexposing the EC for the ambient light by 1 stop and overexposing the FEC by 1 stop. This is usually a good starting point for more dramatic pictures because the background is darker than the subject. • Use flash to balance exposure (ex. If EC is -1/3, then FEC should be +1/3 etc.) Front Curtain Sync • Front Curtain Sync fires the flash right when the shutter opens. This is the “normal” flash mode. • Freezes the action at the beginning of the exposure, then blurs the action. Not good for action shots because it looks unnatural, unless that is the effect you are going for. Rear Curtain Sync • Fires the flash towards the end of the exposure. • Better for action shots where you want to show motion. The ambient light blurs the action then the flash freezes it. • Fires a pre flash. Slow Sync Speed • Allows you to use flash with slower shutter speeds than the minimum (usually 1/60 sec). • Use in a dark setting when you want a bright background and subject. • Or use when you want to pan with action but freeze the subject, giving it a blurry background. • Some cameras have automatic “Party” or “Night” Mode, which just means slow sync. Use at night or inside when you want a bright subject and background. You can light your subject with the flash and use a slower shutter speed to brighten the background Use when panning with an action shot and you want a blurry background. Fast Sync Speed • Allows you to use flash with faster shutter speeds than the maximum (usually 1/200 sec). • Can be used when using a wide aperture outside in daylight while using fill flash. • When shooting action shots and you want the entire photo sharp, you can use a higher shutter speed. Useful when you are using fill flash outside with a wide aperture. Practice • Try different combinations of rear and front curtain sync with slow and high sync speeds. • Experiment with different shutter speeds. • What happens when you use front curtain with slow sync? Rear curtain with fast sync? • Switch your camera to manual mode and try using your own settings. Flash Accessories and Off Camera Flash Diffusion • Flash sometimes looks so harsh because it is a concentrated source of light. Diffusion works by making the area the light is coming from larger. This can be done by using a diffuser, bouncing the flash, or using an umbrella. • On camera flash should only be used in emergencies. Off camera flashes are cheap and work better because the light source is larger. Diffusers • Attach to the flash to spread the light. Can be extremely cheap or fairly expensive. • Try making a diffuser from a white paper bag, a plastic milk jug, or even bubble wrap. Bouncing the Flash • Pointing the flash towards a wall or the ceiling creates a natural look by bouncing and diffusing the light. Try pointing the flash in many different directions for different effects. • Some flashes have a built in white card to bounce the flash off itself. These can be used in a pinch but are usually too small to work properly. • Reflectors can also be used to reflect light, although you need someone to hold it. • Pretty much anything can be used to reflect, such as a piece of paper. Umbrellas • Are fairly cheap and can get professional studio looking photos. • Are large, but light enough to be carried around. • You will need a flash, umbrella, tripod, flash mounting bracket, and flash receivers or cables (if your camera and flash does not have the transmitters built in). • Two different kinds of umbrellas, reflector and shoot through. Shoot Through Umbrellas • More versatile than reflective • Can be moved closer to a subject for more controlled light, or moved farther away to light a whole room. • Try different angles and distances from the subject. Reflective Umbrellas • More effective (brighter and larger area) than shoot through but not as much control. • You can get them in different colors, such as white, silver and gold. Gold is better for skin tones and silver is more intense. White is neutral. Radio Triggers • Allows you to fire your Speedlight while it is off your camera. • Come in infrared an radio. Radio is faster and has a longer usable distance. • Some higher end and newer cameras and flashes have transmitters already built in. • Your built in flash can also be used to fire a Speedlight, the disadvantage being it has to be pointed to the other flash and can add too much light. Choosing a Flash • TTL if you want to be able to set the flash to automatic. • Dedicated flashes (same brand as your camera) have more features, but other brands have 95% of the abilities, are just as powerful, and cost less. • Get the most powerful flash you can afford. • Some have built in wireless receivers. • The Guide Number is how powerful the flash is. • The Recycle Rate is how fast the flash takes to recharge. Guide Numbers • The power of a flash is measured in Guide Number (GN) • GN= aperture x distance • You have to check if it is measured in feet or meters.