- An arc lamp is a device that produces light by the sparking (or arcing, from voltaic arc or electric arc) of a high current between two carbon rod electrodes. The rods are touched and then slowly draw. Used . n apart; as the rods separate the current is "struck" and arcs across the gap in a bright, ionized path. The arc produces a temperature of several thousand degrees, and the tips of the carbon. Used . rods are heated to incandescence, creating light. The rods are slowly vaporized during the process and need to be regularly adjusted to maintain the arc. The concept was first demonstrated by Sir Humphry Davy...Depth of Field
- While a lens focuses on a single plane of depth, there is usually an additional area in focus behind and in front of that plane. This is depth of field. Depth of field increases as the iris is closed.. Used . There is more depth of field the wider the lens and le . Used . ...Joule
- A term in the international system for a unit of electrical, mechanical, and thermal energy equal to the work done when a current of one ampere is passed through a resistance of one ohm for one second. Used . . Surge protectors are often given joule ratings, but this rating refers only to the amount of energy they can absorb, not what gets through. Its value was calculated originally by James Pr. Used . escott Joule, but the term was first introduced by Dr. Mayer of Heilbronn....Subtractive Color
- Subtractive color explains the theory of mixing paints, dyes, inks, and natural colorants to create colors which absorb some wavelengths of light and reflect others. The color that an object appears t. Used . o have is based on what parts of the electromagnetic spectrum are reflected by it, or conversely by what parts of the spectrum are not absorbed.
Anything that is not additive col. Used . or is subtractive color. No other color mixing systems are known, except the imperfect system resulting from mixing real pigments, something that is very confusing nowadays.
Color is not an absolu...Angstrom
- An angstrom, angström, or ångström (symbol Å) is a unit of length. It is not an SI unit. It is accepted (although discouraged) for use with the SI. It is used sometimes used expressing the size of ato. Used . ms, and lengths of chemical bonds and visible-light spectra.
The ångström is named after the Swedish physicist Anders Jonas Ångström (1814–1874), one of the founders of spectrosc. Used . opy. Besides astrophysics, Ångström was also a student of heat transfer, terrestrial magnetism, and the aurora borealis, which was so prominent for him in his northern skies. He created a spectrum chart of sol...