Using any camera in a dull or dark environment generally requires the use of supplementary light. This is a standard technique, and even where adequate natural lighting exists, to take conventional film pictures with enhanced contrast using a fill-in` flash for foreground subjects in shade. A flash is often built into the camera body, but the inte
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rnal flash is not usually powerful enough to illuminate subjects much more that 3 m or so from the camera. On SLR cameras a hot-shoe is provided for triggering an auxiliary, more powerful flash, but the small pocket cameras are not so equipped. However, it is possible to trigger a slave flash from the camera flash by optical means. Even so, things are not so simple, for some cameras, e. g. Olympus, Nikon, Canon actually fire twice, although it appears to be once to the naked eye. The first flash sets the exposure and the second takes the picture. Help on synchronisation requirements may be found at various websites maintained by professional photographers. See also for a series of articles with kits by a caving enthusiast. The presented trigger circuit optically receive the camera flashes and either fires at the same time as the first flash or has one flash delay before triggering the slave flash. Additional counting circuitry is required for more than one delay (covered by modified circuit not presented here). Here`s how it works. The response of phototransistor D5 to the external camera flash is pulsed by a transistorised amplifier T1 into the dual flip-flop clock IC1. One output of a flip-flop illuminates an LED as a ready` signal. A double pole 3-position slide switch, S1, selects none (e. g. for Kodak camera) or one (e. g. for Olympus camera) flash delay before triggering. Both flip-flops are used in the 4013, the...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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