(Article first appeared in Olympus User magazine, UK.)
LIGHT IS THE most important item in the photographers tool kit, without it the camera becomes redundant. So it is just as well that the majority of cameras these days come with their own inbuilt supply. It is worth remembering though, that the humble built-in flashgun is not just a source of light in gloomy situations, it can also be used to great effect to create more interesting pictures. Here we look at the flash options that can be found in many Olympus digital cameras and how to make the most of them.
Flash control
There are two methods of controlling the flash mode on the E-510, either directly using the dedicated button, or via the main control panel. Pressing the button once pops up the flash head and the second press and activates the flash mode options. The options can then be selected using either the buttons, or by turning the control dial. Once the required option is selected press OK to set the flash mode. Alternatively, to set the flash mode using the main control panel, press OK and highlight the flash setting using the buttons, then use the control dial to scroll through the flash mode options. Once the option is selected, lightly press the shutter release to resume the taking mode. When the flash mode is highlighted on the control panel it is also possible to press OK again to bring up the full list of options, the flash mode can then be set using the method described above. Note that when setting a Scene mode () directly on the main control dial the flash settings remain selectable, whereas when set to SCENE the flash mode is locked to a setting appropriate for the Scene mode selected. |
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Menu items
Flash settings on the menu
ISO When set to AUTO the camera selects ISO100 for the majority of situations, but will increase the ISO value to achieve better flash coveragewhere conditions demand. The upper limit for AUTO ISO can be set using the menu’s ISO LIMIT function. |
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Flash settings on the menu
This setting increases or decreases the flash exposure over the normal setting, which is useful for adjusting the flash for difficult subjects. A short-cut to adjusting this setting is to press and hold both the FLASH and +/- buttons at the same time and then turn the control dial to the desired setting. |
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FL BKT
With some subjects it can be difficult to obtain a satisfactory flash exposure straight away. Using this Flash Exposure Bracketing function will allow you to take three consecutive pictures each with a different exposure compensation of either +/-0.3, +/-0.7 or +/-1.0 EV. The first shot will be without exposure compensation, the second will be minus the chosen compensation and the third will be plus the compensation. The LCD will show the amount of compensation as well as a green BKT symbol when the next shot will have exposure compensation applied. Just as with any other exposure compensation, remember to cancel this mode once you have finished using it, otherwise
following shots may be spoilt. |
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Flash settings on the menu
+ This controls how the normal and flash exposure compensation modes work together. When set to ON the total flash compensation amounts to the normal exposure compensation plus the flash compensation. When OFF the normal compensation is ignored and only the flash compensation is applied. |
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X-SYNC
This function allows you to limit the fastest shutter speed that the camera can use for flash synchronisation, in a range of 1/60~1/180th sec. This may be necessary to achieve
synchronisation when using non Olympus flash equipment. |
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AUTO POP UP
The flash head is electronically controlled to pop-up in low light conditions when the flash is required in these exposure modes; AUTO . For all other exposure modes the flash is raised manually using the button. If you prefer the Auto pop-up can be disabled using this menu setting. |
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AF ILLUMINAT.
While not strictly a flash exposure function, the AF Illuminator uses the flashgun to provide additional light to help the AF system to lock on dark subjects. This menu item allows the AF Illuminator to be switched off in situations where it may be inconvenient, eg. in a church. If the AF illuminator is switched off try to focus on a high contrast area of your subject, or switch to manual focus. |
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| Flash range The maximum effective flash distance depends on the maximum aperture of the lens fitted to the camera. To calculate the maximum flash distance use this equation: (Guide Number x ISO Sensitivity) / Aperture value = Distance to subject in meters |
| EXAMPLE: The built-in flash of the E-510 has a maximum guide number of 12 – see table below – (in meters at ISO100), so for example with a 14-42mm f3.5-5.6 lens set to 14mm and ISO100, the maximum flash distance will be (12 x 1) / 3.5 = 3.43m, while at 42mm and ISO400 it will be (12 x 2) / 5.6 = 4.28m. |
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Note when using the built in flash with wide angle lenses there may be a shadow thrown by the front of the lens in the bottom of your picture, this is made worse with close subjects. Avoid fitting a lens hood with these lenses when using flash and zoom in slightly if necessary. |
Flash modes
The flash modes available vary according to the exposure mode set on the main mode dial.
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For exposure modes , P, A and AUTO and the following settings apply ( = no AUTO, , modes available):
AUTO – This will automatically fire the flash (providing it is popped up) when required and automatically control the flash exposure. The flash will not only fire in dark
conditions, but also in backlit situations where the main subject is darker than the background. The flash will synchronise with shutter speeds between 1/30-1/180th of a
second; the shutter speed varies according to the focal length of the lens to help avoid camera shake.
The anti-redeye mode is the same as AUTO but with a series of pre flashes before the main flash exposure. These pre flashes contract the pupils of your subject’s eyes and reduce the amount of light reflected from the retina, therefore reducing the red-eye effect.
This mode is useful for using flash to fill in the shadows of pictures taken in bright sunlight, or backlit subjects. The flash is forced to fire whatever the brightness of the subject, however the shutter speed will be limited to between 1/30-1/180 second. With careful selection of aperture value to keep within this shutter speed range, you can achieve a good exposure for both the naturally lit areas and the areas illuminated by flash. It can sometimes be worth using the flash exposure compensation to under-expose the flash slightly to give a more natural look to the shadows.
Flash Off; the flash will not fire even if the flash is popped up. The AF illuminator flashes will still fire if required and the AUTO POP-UP still operates for the AF Illuminator unless either function is switched off.
SLOW This mode allows normal flash exposure for the foreground with a longer shutter exposure to correctly expose a dark background; ideal for taking a portrait with a night time backdrop. As the shutter speed is no longer limited to prevent camera shake (exposures up to 60 seconds), use a tripod or place the
camera on a firm surface to prevent movement. You could of course engage the E-510’s Image Stabilisation function (not when using a tripod), but even this may not cope with hand held shots of a few seconds or more. As this is a red-eye reduction mode a series of pre-flashes are emitted before the main flash.
SLOW This is similar to the ‘Red-eye slow sync’ mode but without the pre-flashes. This is suitable for subjects with no people in the foreground, but where foreground flash is still required, along with a time exposure for the distant background.
SLOW2Unlike all the other flash modes where the flash fires as soon as the shutter is fully open, this mode sets the flash to fire just as the shutter (2nd curtain) is about to close. This is useful for long exposures of moving objects, such as with cars, when trails of light are left behind the subject which is subsequently frozen in motion by the flash. This looks more natural than photos taken using other flash modes, which would show the light trails projecting forward from the lights as they would have been created after the flash had fired. With conventional 1st curtain sync any motion blur will occur after the flash has fired.Just as in the other slow sync modes, the flash is automatically controlled to fire in low light and backlight situations and the flash exposure is automatic as well.
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FULL, 1/4, 1/16, 1/64 These are manual flash modes with different levels of output power. The flash will always fire and the shutter speed will range between 1/180th and 60 seconds. The lower power settings can be used for fill in flash, or to just put a highlight in the eye of your subject to add a little life. To calculate the Guide number (flash power) to use with the selected aperture follow this calculation: (Aperture Value x Distance to subject in meters) / ISO Sensitivity = Guide Number
Where the guide numbers are:
| Power Setting |
Full |
1/4 |
1/16 |
1/64 |
| Guide Number |
12 |
6 |
3 |
1.5 |
And ISO sensitivity:
| ISO Value |
100 |
200 |
400 |
800 |
1600 |
| ISO Sensitivity |
1.0 |
1.4 |
2 |
2.8 |
4.0 |
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For exposure modes M and S the following flash setting are available:
In shutter priority auto and manual exposure modes the fastest shutter speed is automatically limited to 1/180th second whenever the flash is popped up to prevent flash cut-off. Slower speeds down to 60 seconds can be selected.
Just as with Program and Aperture priority exposure fill-in (forced) flash, the TTL Flash metering will regulate the flash output to give a correct flash exposure. Again when shooting in daylight careful selection of Shutter speed, Aperture and ISO will be necessary to achieve the correct balance of exposure.
As above but with red-eye reducing pre-flashes.
Flash off (except for AF Illuminator)
SLOW2 – Forced flash with 2nd curtain synchronisation
FULL, 1/4, 1/16, 1/64 – See the manual flash modes previously described. When using manual exposure mode you can calculate the required aperture for any flash power setting using this calculation: (Guide Number x ISO Sensitivity) / Distance to subject in meters = Aperture value |
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