Using a Slave Flash with a ”Point & Shoot” style camera
by M/Sgt Hayden B. Baldwin, Illinois State Police
The Point & Shoot style digital camera has a built-in flash sufficient for distance of 10 feet or less. The built in flash range is limited. However, with a slave flash, the distance can be increased to 18, 25, even 40 feet...depending on the flash used as a slave flash.
A slave flash is ANY photographic flash attached to a slave unit. A slave unit has a sensor built into the unit that is flash sensitive. The slave unit can “sense” when a photographic flash has been fired. The slave unit then closes its circuit and activates whatever flash is attached to it. Most are so sensitive that they can be activated 100 feet away in full sunlight!
The photographer uses an auxiliary camera handle that has an attached a hot shoe. A screw mounts the camera to the handle. The slave unit fits into the hot shoe handle and the flash is mounted on the slave unit. In this configuration the flash on the camera activates the slave flash. When the flash on the camera fires so will the slave flash, all happening within 1,000 to 10,000 of a second, depending on the brand of the flash.
All flashes have flash guide numbers. These guide numbers divided into the film speed will give you the maximum distance for the flash.
A Vivitar 283 flash has the following specifications according to the owners manual. The flash guide number for an ISO of 125 is 135. Dividing the flash guide number of 135 by the fixed f-stop of 5.6 the answer is 24.1 feet. Therefore, using a Vivitar 283 flash set on manual, the photographer can be up to 24.1 feet away from the subject. If the Vivitar 283 flash is set on automatic than the light sensor in the flash can automatically adjust to the distance of the subject. Again referring to the owner’s manual of this flash, the manual states the 5.6 f-stop is compatible to the “red” setting on the flash. This setting will automatically adjust the light intensity of the flash from 4 feet to 30 feet from the subject. I would suggest the automatic mode be used for most lighting conditions. Most photographic flashes are rated for 100 ISO film. You will need to read their individual manuals to determine what their flash guide rating is for an ISO of 130. The “better” the flash the more distance you can be from the subject, within limitations. Even jumping to a high end flash unit, the most you will get is about 40 feet from the subject with this camera.
Using a slave flash is not restricted to outdoor use only. It should also be used on any indoor photos that the subject is greater than 10 feet from the camera. This extra lighting will greatly improve your photographs. This technique is good for all point & shoot cameras, including all disposable cameras.
Digital Slave flashes such as this, SF8 are made specifically for digital cameras. Or digital flashes are specifically made to act as slave flashes such as those from Digi-Slave . Slave flash sensors are not all the same. Some digital cameras built in flashes have actually two flashes. The first flash is to preset the white balance or focus and the second flash is for exposure. You may need to experiment to find which style of slave sensor will work with your camera.
Since this article was written the Vivitar 283 was replaced with Vivitar 285.
Here are a couple examples: