Flash (photography)

The high-speed wing action of a hummingbird hawk-moth is frozen by flash. The flash has given the foreground more illumination than the background; Image exposed without additional lighting (left) and with fill flash (right); Lighting produced by direct flash (left) and bounced flash (right):

A flash is a device used in photography producing a flash of artificial light (typically 1/1000 to 1/200 of a second) at a color temperature of about 5500 K to help illuminate a scene. A major purpose of a flash is to illuminate a dark scene. Other uses are capturing quickly moving objects or changing the quality of light. Flash refers either to the flash of light itself or to the electronic flash unit discharging the light. Most current flash units are electronic, having evolved from single-use flashbulbs and flammable powders. Modern cameras often activate flash units automatically.

The color temperature of the electromagnetic radiation emitted from an ideal black body is defined as its surface temperature in kelvins, or alternatively in micro reciprocal degrees (mired). This permits the definition of a standard by which light sources are compared.

光源一般都偏色，没有正白的。女性一般喜欢烛光，颜色偏红偏粉柔和，低亮度还营造暧昧氛围。现在许多显示器/手机屏幕有护眼滤蓝光模式，开到最大后颜色会变得相当黄。

Flash units are commonly built directly into a camera. Some cameras allow separate flash units to be mounted via a standardized "accessory mount" bracket (a hot shoe). In professional studio equipment, flashes may be large, standalone units, or studio strobes, powered by special battery packs or connected to mains power. They are either synchronized with the camera using a flash synchronization cable or radio signal, or are light-triggered, meaning that only one flash unit needs to be synchronized with the camera, and in turn triggers the other units, called slaves.

A typical electronic flash unit has electronic circuitry to charge a high-capacitance capacitor to several hundred volts. When the flash is triggered by the shutter's flash synchronization contact, the capacitor is discharged rapidly through a permanent flash tube, producing an immediate flash lasting typically 1/1000 of a second, shorter than shutter speeds used, with full brightness before the shutter has started to close, allowing easy synchronization of full flash brightness with maximum shutter opening. Synchronization was problematic with bulbs, which if ignited simultaneously with shutter operation would not reach full brightness before the shutter closed.

柔光罩也叫闪光灯散射罩，它可以把闪光灯打出来的光线变柔和，使照片看起来更加自然……闪光灯直射光线通过耐高温的半透明塑料…… 重点：塑料。可用香皂盒代替。还可以蒙块布、丝袜啥的。

Ring flashes that fit to a camera's lens can be used for shadow free macro photography [微距摄影], There are a few lenses with built-in ring-flash. In a photographic studio, more powerful and flexible studio flash systems are used. They usually contain a modeling light [造型光], an incandescent light bulb close to the flash tube; the continuous illumination of the modeling light lets the photographer visualize the effect of the flash. A system may comprise multiple synchronised flashes for multi-source lighting.

制约大多数人摄影水平的不是器材而是技术。摄影是最容易入门的艺术，小提琴可能是最难的。下图是一个素描入门基础画：

In photography, bulb is named for the bulb on detachable rubber pneumatic shutter releases that came with early cameras. With shutters set to "B", the pneumatic release kept the shutter open for as long as the photographer squeezed the bulb—a "Bulb" exposure. Bulb是以早期相机附带的可拆卸橡胶气动快门释放装置上的灯泡命名的。当快门设置为“B”时，气动释放装置使快门保持打开状态，直到摄影师挤压bulb——一个“Bulb”曝光。[长得像血压计用的那种橡胶球，以形状命名。]

A more modern (circa 1950) camera cable release; Squeeze the bulb to release the shutter; A bulb shutter release

请问怎样选购单反相机的闪光灯？ 我想买个便宜的国产闪光灯，请问有的闪光灯支持高速同步是什么意思？ - 知乎

职业摄影师永远不会告诉你的拍摄技巧 篇三：闪光灯拍摄技巧_闪光灯_什么值得买 TTL=Through The Lens. [我推荐国产或原厂低端，总之便宜就好。Again, 摄影是最容易入门的艺术，花2万买器材想表现什么？不如花1万买器材，另1万买个大金链子(更保值)。我觉得他引以为豪的第二张照片傻白傻白的。]

永诺的镜头也不错。