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Electronic flashlight devices

The basic theory by which all electronic flash light devices operate is summarized in the condensation (storage) of large electrical energy by means of an electric condenser, then this electrical energy is released once and it is transformed by the electronic flash light lamp (sometimes called the flash tube) into Very strong light energy that takes only a thousandth or several thousandths of a second (ranging in the usual types between 1/1000 to 1/10000 of a second). This valve requires a high voltage difference of approximately 2500 volts. As these devices use batteries of small types that cannot generate a high-voltage electric current such as 2500 volts, so it is necessary to follow some steps to convert the simple electrical current generated from the battery into a current with a high voltage difference suitable if the flashing light valve flashes. We show these steps below:

(a) There is a battery in the electronic lighting device that generates a continuous electrical current, D.C., with a low voltage difference.

(b) In order to convert the continuous electrical current with a low voltage difference into a current with a large voltage difference, it is necessary first to convert the direct current .D.C. into an intermittent current (A.C. i.e. Alternative). This is done by passing the current through the Vibrator oscillator to convert the direct current into an intermittent current .

(c) The intermittent current is then passed through a transformer to transform it into a high voltage.

(D) After converting the intermittent current into a current with a high voltage difference (approximately 2500 volts), it is thus converted into a continuous current with a high voltage difference also by means of a rectifier, then it is stored in the condenser.

(e) By connecting the electrical energy of high voltage difference to the valve of the Electronic Flash Tube, this electrical energy is discharged and turns into very strong and very fast light energy, as we mentioned.

Using normal electric current to operate flashlight devices:

The batteries of the flashlight devices need to be recharged whenever they are used for a period of time, so some types of these devices are prepared to work directly by means of the mains electric current if it is possible to obtain it, and thus we can summarize the work of the electronic flashlight device in the following steps:

(a) Converts the main intermittent current (and its voltage usually does not exceed 230 volts) into an intermittent current with a high voltage of 2500 volts.

(b) Since the condenser cannot be charged with an intermittent current A.C. Therefore, this current is converted from intermittent to continuous with a high voltage difference (2500 volts) by means of the retifier

(C) This continuous current (with a voltage difference of 2500 volts) is stored in the condenser and is prepared to be discharged to convert into light energy, as previously mentioned by the condenser.

Adjusting the camera when using electronic flashlight:

We knew before that there is a time that passes between the moment the photographer presses the shutter trigger and the flash of light reaching the top, and we learned that the term used to express this time is (delay).

And since this delay is so short in the case of an electronic flash of light that it can be completely neglected, that is why we set the press on the camera to Synchronisation (1). It follows that the negative image will come out completely white and transparent, especially if the electronic flash light is the only source of illumination.

And where the characteristics of the flash light suitable for the focal plane shutter differ from the nature of the electronic flash light, which takes only a fraction of a second (usually about 1/1000 of a second), while exposing the sensitive film takes a relatively long time when using the focal plane shutter, so the light is not considered The electronic snapper is an appropriate method for imaging with a focal plane diaphragm unless there is a special setup to accommodate the two.

When is flash light used?

Flash light is used in photography for one of the following reasons:

1- If strong natural or artificial lighting is not available, flickering light is used and relied upon as the main source of light.

2- As an auxiliary light source for lighting areas of shadows resulting from the main source, and at that time it is considered a secondary light source.

3- As a means of recording very fast movements that the maximum shutter speed of the camera cannot be recorded.