IGBT ADVANTAGES Geplaatst op 24 September 2017 Door Paul. C. Buff 0 IGBT ADVANTAGES Even the most expensive professional monolight flash units usually control flashpower by varying the voltage applied to the flash capacitors. This simple and inexpensive method has three distinct limitations to the achievement of truly professional performance: 1. The range of power reduction is typically limited to 1/8 to 1/32 power, often resulting in an inability to achieve low aperture settings with close lighting techniques. 2. As power is reduced, the flash duration becomes longer - typically twice as long at minimum power relative to maximum power. Th e median t.1 flash duration of the ten most popular pro monolights ranges from 1/200 second to 1/400 s econd – too slow for sharp freezing of action in sports, dance and other rapid movement shots. 3. Color temperature typically varies by 75ºK to 80ºK per f-stop of power reduction, resulting in about 400ºK color difference between minimum and maximum power. The Einstein unit employs proprietary advanced digitally controlled IGBT technology to control flashpower. This results in an extreme range of power reduction (1/256 power) in precise 1/10f stops. As power is reduced, the t.1 flash duration also decreases dramatically instead of increasing. This technology allows the Einstein unit to maintain a constant color temperature throughout the entire 256:1 power range.Two operating modes are provided – ACTION Mode and CONSTANT COLOR Mode. In Action Mode, the t.1 flash duration shortens rapidly from 1/588 seconds at full power to 1/13,500 seconds at minimum power for incredible action freezing capability, but the color temperature increases as power is reduced. In Constant Color Mode, the t.1 flash duration drops less rapidly, to a minimum of 1/8000 second, while maintaining a constant color temperature of 5600ºK (+/- 50ºK) throughout the entire power range. The internal processor controls the accuracy and repeatability with very high precision. ACTION Mode: In Action Mode, the color temperature rises as power is reduced, but the t.1 flash duration is minimized even further for maximum action stopping capability where absolute color consistency is secondary to motion freezing. At 1/2 power in Action Mode, the t.1 flash duration is approximately 1/2000 second and the color temperature is approximately 5750ºK (absolute values of flash duration and color temperature are indicated on the rear LCD display). CONSTANT COLOR Mode: In this mode, the emitted color temperature is held constant at 5600ºK, plus or minus 50ºK at any power setting or input voltage. At full power, the t.5 flash duration is 1/1600 second and the t.1 time is 1/568 second. As power is reduced to 1/2 power the color remains constant, while the flash duration decreases to 1/1351 second t.1 (note that with IGBT control, the t.5 spec is no longer meaningful, so only the t.1 flash duration appears on the rear LCD display). As power is further decreased, the color temperature remains constant and the t.1 flash duration falls ultimately to 1/8000 second at the lowest power settings.