Watt
A second is an alternative unit of energy, equal to the joule.
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Joule (Watt-second)
Techniques Glossary Joule (Watt-second)
Indicates the energy content of the storage capacitors in an electronic flash. One Joule is the light output given by one watt burning for a second.
What are watt-seconds, and how many do you need? Mark Wallace takes several minutes to explain watt-seconds, how they influence the amount of light emitted by a flash, and what other factors may effect light intensity.
Watt
The unit of power W, i.e. the amount of energy dissipated (used) or delivered in unit time. 1 Watt = 1 Joule per Second.
Water Paper ...
watt
a unit of electrical power; one watt is equivalent to the power represented by one ampere of current with a pressure of one volt in DC circuit or one absolute joule per second and equal to 1/746 horsepower.
Watt (w)
A measurement of power or the rate at which electrons move along a wire. Tip: Different types and makes of fixtures using the same wattage lamps when tested at the same distance will have considerable variations in light output.
+ 15- watt bulb at 6.5 ft.
With my setup, the supplementary weak exposure for Kodalith was 0.3 second at 25 volts with a 60- watt bulb at 4 feet; for Tech Pan, 0.
Use 40 watt and 60 watt bulbs for the lamps. Be aware that you probably can't go 'green' and use low wattage bulbs. The light will be different. If you have a digital camera, you might be able to adjust for this by adjusting your white balance.
Watt per second. For flash mode, the measurement of electrical energy in the flash.x
X (setting) ...
Watt second / Joule ratings can be very misleading as they relate to the supplied electrical power and not the actual light output. Guide numbers are often not much better because they depend on conditions and reflectors defined by each manufacturer.
Watt is a unit of power in electricity.
Watt-second is an alternative unit of energy, equal to the joule.
A Watt steam engine in Madrid. The development of the steam engine propelled the Industrial Revolution in Britain. The steam engine was created to pump water from coal mines, enabling them to be deepened beyond groundwater levels.
Jim Watt
Jim is a vocal supporter of digital photography, for no reason other than the contagious excitement digital imaging brought back into his career as a stock photographer.
However, 600 watt quartz halogen lights are pretty bright and operate under the same principle as regular tungsten bulbs. The difference is the bulbs are made of quartz and are filled with halogen gas. The result is brighter light and longer life.
1 Jy = 10-26 Watt Hertz-1metre-2. Jets Perhaps the weirdest feature of AGN is that they can produce narrow jets of material streaming outwards from the centre.
CowboyStudio 330 Watt Three Light Kit: $290.99
3 Monolight Studio Flash/Strobes
3 Softboxes
1 Boom Kit w/Sandbag
1 24″ Photo Tent ...
-Photographic processing sink Use only the size of incandescent bulb specified; for example, 7 1/2 watt, 15 watt, or 25 watt. Handle sensitized material at the distance recommended by the manufacturer. This is usually between 3 and 6 feet.
The points to watch for are the power of the units measured in watt seconds. 320 watt seconds per unit is very adequate; you can get away with 160 watt seconds at a pinch. The more power, the more light. The light stands should be sturdy.
In the studio I sometimes use a couple of 250 watt blue lights (daylight balanced) in 10" reflectors to light up a much larger piece of matte board. In this case I will position the matte board and lamps well behind the subject.
The shot was made with one light-a 100 watt light bulb-and it is the same light that appears in the image. It was shot on film against a white background for a magazine layout.
I bought one at a large local hardware store with two 500-watt bulbs for less than $50. It certainly generates a lot of heat, but it puts out a lot of light as well.
Example: You enter a pitch-black room and turn on a 100-watt light; you see a fixed amount of light intensity, as would a digital camera. You then turn on a second 100-watt light, thus doubling the light output.
I have a 500 W/s (Watt-second) system which is all the power I need; I usually turn it down to 250 W/s for faster recycling. Today you can get them in 240, 400 and 600 Watt models, any one of which ought to be fine.
The power of these units is usually specified in watt-seconds. The higher the rating, the more powerful the unit. Another important attribute is the unit's recycle time. The shorter the time, the faster you can get off the next shot.
3 Light Heads with 1000 Watt Quartz Bulbs
3 Sturdy Light Stands
3 Easy to Vented Assemble Soft Boxes with Metal Attachment Rings
Padded Carrying Case ...
1950′s Ice-O-Matic ice crusher body, Bakelite coffee pot handle, Watt gauge, Brownie Hawkeye camera, pair of motorcycle control levers, extrude aluminum stock and a pair of candle holders.
Walter - aka The Lung ...
80A - Perfect for indoors lit by 100 watt (or less) incandescent bulbs. Converts 2900K to 4680K, but loses about 2 stops.
Unit used to quantify the light output of electronic flash. A joule is equal to one watt second of 40 lumen-seconds. The measure is used to compare flash units in terms of power output.
JPEG: ...
Smith Victor KT750 3-Light 750-Watt Thrifty Photoflood Kit with Corrugated Carrying Case ...
Last winter I started experimenting with indoor floral macros, using flowers purchased locally, black cardboard and/or drop cloth, typical 60 watt light bulb (I use a lamp with a flexible head so I can easily reposition to get just the right angle), ...
Flash unit capacity is also described in terms of light output units such as beam candlepower seconds (BCPS) or effective candlepower seconds (ECPS) or in terms of energy capacity units such as joules or watt-seconds.
What I did to keep the drum warm is to place a gooseneck lamp with a 100-watt light bulb over the drum during the processing.
The output of a flashgun Is usually quoted either In terms of a guide number or an aperture at a set distance, with a particular film speed (usually 100 ASA), although Ikelite also specify the output of their models in watt/seconds.
Unfortunately you can't just stick a 200 watt red light in your darkroom and wonder what all this " dark" business is about.
 See also: Light, Photograph, Photography, Image, Camera
  
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