A monolight is a self-contained
photographic flash
A flash is a device used in photography that produces a brief burst of light (typically lasting 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 ...
lighting unit
[StudioLighting.net](_blank)
/ref> usually found in a studio
A studio is an artist or worker's workroom. This can be for the purpose of acting, architecture, painting, pottery (ceramics), sculpture, origami, woodworking, scrapbooking, photography, graphic design, filmmaking, animation, industrial design ...
. Each monolight has its own independent power source. It does not depend on a centralized power supply as a "pack and head" system does. Monolights are also independently controlled: each has its own power settings and light output. Flash power is predominantly measured by the industry in watt second
The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force applied ...
s, which is unit-equivalent to the joule
The joule ( , ; symbol: J) is the unit of energy in the International System of Units (SI). It is equal to the amount of work done when a force of 1 newton displaces a mass through a distance of 1 metre in the direction of the force applied ...
.
Construction
A simple monolight at a minimum consists of a power supply, power connector, and flash tube. Most monolights have a fairly common set of features, described below.
Common features
Most monolights have several features in common:[Guided Tour of a Monolight](_blank)
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* Flashtube/strobe bulb — The bulb that creates the flash.
* Modeling light — A constant light that illuminates the subject and aids the photographer in composing the picture.
* Power connector — The receptacle for the power cord.
* Power switch — A switch to turn the monolight on and off.
* Slave sensor — A sensor that detects the flashes of other strobes and triggers the strobe of which it is a part.
* Reflector — A device which modifies the light, allowing it to bounce off of a shiny surface.
* Stand socket — A device on the bottom of the unit that allows it to be mounted on a standard light stand.
* Umbrella socket — A receptacle into which is inserted a light-modifying umbrella.
Additional features
In addition to those features listed above, monolights may also have the following features:
* Output control - Allows the intensity of the flash to be adjusted down or up to the maximum power output of the flash unit.
* Model light tracking - Allows the modeling light to increase and decrease with the strobe when the strobe fires.
* Auto dumping – the ability to partially discharge the light’s capacitors when the output power is reduced. Without this feature, when the light's output is turned down, it has to be fired to fully discharge the capacitors, then the capacitors recharged up to the new lower level.
* Power recycle indicator - A light or sound emitter or both which tell the photographer that the flash has fired, and is currently charging.
* Remote control - either wired (through a telephone jack
A telephone jack and a telephone plug are electrical connectors for connecting a telephone set or other telecommunications apparatus to the telephone wiring inside a building, establishing a connection to a telephone network. The plug is inserted ...
to a handheld control) or wireless. Remotes may allow the user to adjust light output, modelling lamp intensity, etc.
Considerations of a good monolight
Monolights are photographic flashes and therefore carry some of the same considerations as a standard flash unit. A primary concern is guide number
When setting photoflash exposures, the guide number (GN) of photoflash devices (flashbulbs and electronic devices known as "studio strobes", "on-camera flashes", "electronic flashes", "flashes", and "speedlights")The Nikon brand name for its came ...
. Each monolight has a guide number specifying its range at certain film speeds. A common misconception is that the watt-second measurement is an indication of light output. It is not; it is a measure of electrical energy.[Hi-Tech Studio: Monolights , Digital Photo Pro Magazine](_blank)
/ref> While the electrical energy used in firing the flash is usually the most significant factor, light output is also affected by the efficiency of the flash tube and the capacitor.
In addition to power output, monolights have other, special considerations as they are meant to be used for large-scale, studio work. Portability, consistency, feature set, parts availability and cost are prime considerations in monolights.
Portability
Monolights are larger than most on-camera strobes. As such certain portability issues must be considered:
Size and weight
Monolights are sometimes referred to as monoblocks
/ref> due to the containment of all power and controls in each individual flash unit. Consequently, monolights usually weigh more than on-camera flashes. As monolights need to be placed on light stands, the size and weight of each light stand must also be considered. This size and weight must also be weighed against a pack and head system, which typically have a much weightier generator box.
Power requirements
Monolights are independently powered and therefore require individual power connections. Monolights become less practical in situations where power outlets are scarce.
Consistency
Monolight consistency refers to the power output of the unit from flash to flash. Good monolights will vary little from one flash to another.
/ref> Monolights that vary greatly (more than 1/5 of an f-stop
In optics, the f-number of an optical system such as a camera lens is the ratio of the system's focal length to the diameter of the entrance pupil ("clear aperture").Smith, Warren ''Modern Optical Engineering'', 4th Ed., 2007 McGraw-Hill ...
) are said to be inconsistent. Inconsistent monolights makes computing the appropriate aperture next to impossible due to the variable light output.
Since monolights often vary the capacitor charge to vary the light output, lower voltage through the tube can affect the flash's color temperature. Some units have electronics to compensate and maintain a steady color temperature through the power range.
Features
A monolight's features make it more versatile, but it also makes a monolight more expensive. A good monolight generally has all the features listed above in the Common Features section.
Availability of accessories and parts
Procuring replacement parts and accessories for monolights is also a consideration. Monolights made by mainstream companies generally have a higher parts availability in more places than off-brand products. This is a strong consideration when using monolights on a location shoot. Accessories tend to be more readily available for on-brand monolights.
References
External links
Walk around the Monoblock part 1 of 2
Strobist explains how to use monolights (monoblocks) and when they are sometimes preferable to speedlights.
{{Photography
Flash photography
Photographic lighting