* Photographic filter, a camera accessory consisting of an optical filter that can be inserted in the optical path

This subsystem consisted of 4 parts, a Cassegrain telescope with a 1. 05 ° by 1. 05 ° field of view, a shutter and red / green filter assembly with 0. 08s and 0. 20s exposure times, a slow scan vidicon tube which translated the optical image into an electrical video signal, and the electronic systems required to convert the analogue signal into a digital bitstream for transmission.

The analog optical image intensity function which is sampled by the sensor device is not in general bandlimited, and the non-ideal sampling is itself a useful type of low-pass filter, though not always sufficient to remove enough high frequencies to sufficiently reduce aliasing.

When the area of the sampling spot ( the size of the pixel sensor ) is not large enough to provide sufficient spatial anti-aliasing, a separate anti-aliasing filter ( optical low-pass filter ) is typically included in a camera system to further blur the optical image.

An interference filter or dichroic filter is an optical filter that reflects one or more spectral bands or lines and transmits others, while maintaining a nearly zero coefficient of absorption for all wavelengths of interest.

Equipped with a stepper motor and electronics, a tunable optical filter that tunes center transmission wavelength over C-band or L-band by remote control can be achieved.

See diagram below for its working principle and tunable optical filter devices

Working principle of a tunable optical filter based on rotating interference filter.

The best strategy for observations might be to wait for the planet's transit of the Sun's disk, and then observe through a strong optical filter.

Hall used a 1 / 8 inch Tiffen Black ProMist filter for almost every scene, which he said in retrospect may not have been the best choice, as the optical steps required to blow Super 35 up for its anamorphic release print led to a slight amount of degradation ; therefore, the diffusion from the filter was not required.

Most current consumer digital cameras use a Bayer filter mosaic in combination with an optical anti-aliasing filter to reduce the aliasing due to the reduced sampling of the different primary-color images.

* Petrographic microscope, whose design usually includes a polarizing filter, rotating stage and gypsum plate to facilitate the study of minerals or other crystalline materials whose optical properties can vary with orientation.

This grating acts like an optical filter, causing a single wavelength to be fed back to the gain region and lase.

In 1989, the European Space Agency's Hipparcos satellite took astrometry into orbit, where it could be less affected by mechanical forces of the Earth and optical distortions from its atmosphere.

The atoms should then be irradiated by optical radiation, and the radiation source could be an element-specific line radiation source or a continuum radiation source.

In March 1974, during a meeting of the audio group, two engineers from the Philips research laboratory recommended the use of a digital format on the 20 cm optical disc, because an error-correcting code could be added.

In 1914, Werner resolved the first coordination complex, called hexol, into optical isomers, overthrowing the theory that only carbon compounds could possess chirality.

The latter hypothesis seems the more plausible evolution determinant as the surface area of the head is minute compared to the remainder of the body, thus the energy required in producing long hair for the express purpose of " optical " amplification of UV light reflected from the snow seems counterproductive ( however, it's very likely that the trait was sustained due to a nuanced combination of multiple influences, given that human hunting-skills and ingenuity were such by 50, 000 years ago that said benefits in terms of ' comfort ' could have alternatively been derived from constructing head and ear warmers of fur from prey, etc .).

However, exactly 100 years after Braid introduced the method, another expert could still state: " It can be safely stated that nine out of ten hypnotic techniques call for reclining posture, muscular relaxation, and optical fixation followed by eye closure.

One of the earliest of these was Al-Kindi ( c. 801 – 73 ) who wrote on the merits of Aristotelian and Euclidean ideas of optics, favouring the emission theory since it could better quantify optical phenomenon.

Spectacle makers created improved types of lenses for the correction of vision based more on empirical knowledge gained from observing the effects of the lenses rather than using the rudimentary optical theory of the day ( theory which for the most part could not even adequately explain how spectacles worked ).

Kuhn used the duck-rabbit optical illusion to demonstrate the way in which a paradigm shift could cause one to see the same information in an entirely different way.

The attraction of this approach was that it was thought to be faster than an optical laser, which could only shoot down warheads one at a time, limiting the number of warheads each laser could destroy in the short time ' window ' of an attack.

Consequently, the thin optical surface layer could be quite different from the regolith underneath, and not representative of the bulk composition of the body.

** In Holmdel, New Jersey, scientists at Bell Labs announce they have created a digital optical processor that could lead to the development of superfast computers that use pulses of light rather than electric currents to make calculations.

In 1874, Jacobus Henricus van't Hoff and Joseph Achille Le Bel independently proposed that the phenomenon of optical activity could be explained by assuming that the chemical bonds between carbon atoms and their neighbors are directed towards the corners of a regular tetrahedron.

In a single-mode fiber, measuring a shorter cutback fiber could result in significant transmission of cladding modes ( light carried in the cladding rather than the core of the optical fiber ), distorting the measurement.

Using a less strict definition of the electro-optic effect allowing also electric fields oscillating at optical frequencies, one could also include nonlinear absorption ( absorption depends on the light intensity ) to category a ) and the optical Kerr effect ( refractive index depends on the light intensity ) to category b ).

Semiconductor optical amplifiers are typically made from group III-V compound semiconductors such as GaAs / AlGaAs, InP / InGaAs, InP / InGaAsP and InP / InAlGaAs, though any direct band gap semiconductors such as II-VI could conceivably be used.

This technique could greatly improve optical modulators, increasing the density of information carried by optical fibers.

This would reduce the need for field splicing, which could greatly reduce the amount of hours necessary for placing an optical fiber cable in a telecommunications network.

The technology behind these methods have evolved, from panels at the fire department ( which could trigger and control green lights for certain major corridors ) to optical systems ( which the individual fire apparatus can be equipped with to communicate directly with receivers on the signal head ).

Also listed here are unexplained phenomena that could have an optical explanation and " optical illusions " for which optical explanations have been excluded.

The next development in optical theory came in 1899 when Max Planck correctly modelled blackbody radiation by assuming that the exchange of energy between light and matter only occurred in discrete amounts he called quanta.

Fiber optic transmission systems use lasers to transmit signals over optical fiber, and a high optical return loss ( ORL ) can cause the laser to stop transmitting correctly.

He conducted visual experiments using marked circular disks which led him to conclude, correctly, that the viewing of canals arose as an optical illusion.

In 1967, before the discovery of pulsars, Shklovsky examined the X-ray and optical observations of Scorpius X-1 and correctly concluded that the radiation comes from an accreting neutron star.

SDLT adds an optical servo system that reads servo patterns on the back of the tape to keep the data tracks on the front of the tape correctly aligned with the read / write heads.

In 1967 ( before the discovery of pulsars ), Iosif Shklovsky examined X-ray and optical observations of Scorpius X-1 and correctly concluded that the radiation comes from a neutron star accreting matter from a companion.

The electron optical system may be either a magnetic or electrostatic one.

It should be noted, however, that the paraxial resolution is quite similar for both electron optical systems.

Settled phosphors, as generally used in image intensifiers, have low optical contact with the substrate surface, hence Af shall be assumed.

It must be remembered that the fiber plates replace a glass window and a ( mica ) membrane, in addition to an optical output lens system.

However, the leveling operation can be maintained and controlled remotely with no mechanical or optical contact with the platform.

It is clear from this discussion that cosmologists of every persuasion look hopefully toward the day when a man-made satellite can be equipped with optical devices which will open up new vistas to science.

Several other oxidation states are known, which range from + 2 to + 7 and can be identified by their characteristic optical absorption spectra.

As with many scientific fields, strict delineation can be highly contrived and atomic physics is often considered in the wider context of atomic, molecular, and optical physics.

The and convention for amino acid configuration refers not to the optical activity of the amino acid itself, but rather to the optical activity of the isomer of glyceraldehyde from which that amino acid can, in theory, be synthesized (- glyceraldehyde is dextrorotary ;-glyceraldehyde is levorotatory ).

Microscopy can be categorized into three different fields: optical microscopy, electron microscopy, and scanning probe microscopy.

Let S ( fig. 5 ) be any optical system, rays proceeding from an axis point O under an angle u1 will unite in the axis point O ' 1 ; and those under an angle u2 in the axis point O ' 2.

When used in such fashion, beacons can be considered a form of optical telegraphy.

* the bandwidth of the output of some light source, e. g., an ASE source or a laser ; the bandwidth of ultrashort optical pulses can be particularly large

* the width of the frequency range that can be transmitted by some element, e. g. an optical fiber

Lastly, mechanical properties of these biopolymers can often be measured using optical tweezers or atomic force microscopy.

Guidance can be mechanical, optical or electromagnetic.

Such particles are normally invisible in an optical microscope, though their presence can be confirmed with the use of an ultramicroscope or an electron microscope.

Micrometre-scale colloidal particles are large enough to be observed by optical techniques such as confocal microscopy.

In addition, phase transitions in colloidal suspensions can be studied in real time using optical techniques, and are analogous to phase transitions in liquids.

The technique involves using optical lasers to create an interference pattern, which acts as a " lattice ", in which ions or atoms can be placed at very low temperatures.

Among his results, Gauss showed that under a paraxial approximation an optical system can be characterized by its cardinal points and he derived the Gaussian lens formula.