Modified camera records lens settings on film
Camera is modified by inserting optical imaging system between lens and film. This system requires no electrical power, is low in weight, and adds nothing to external size of the camera.
Thompson, R. E.↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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High temperature lens construction Patent
Lens assembly for solar furnace or solar simulator
Lorell, K. R.↗
Petzval type objective including field shaping lens Patent
Development and characteristics of Petzval type objective including field shaping lens for focusing light of specified wavelength band on curved photoreceptor
Coniglio, G. V.↗
Low scatter lens design/development
The criteria for the optimum design of optical systems are discussed along with the selection of appropriate materials. The construction details of low scatter lens systems are tabulated. Scattering analysis; total energy diffracted; and computation of delta for a scratch, bubble, and microscopic irregularities are also discussed.
Gallipeau, R. B.↗
Optical design computer program: LENS II
Differential-correction program evaluates optical lens design.
Source record↗
Development of the design of a between-the-lens band type photographic shutter
When photographic equipment is miniaturized, in order to conserve weight and size for spacecraft use, by using wide angle, short focus lenses, a band-type central between-the-lens shutter must be used. The rectangular slot shape was the form with the highest optical efficiency. To overcome the problem of burrs caused in the punching out of the slots in a carbon steel band, a shape limited by arcs with radius equal to half the slot width is preferred.
Dorofeyev, A. S.↗
Prototype color field sequential television lens assembly
The design, development, and evaluation of a prototype modular lens assembly with a self-contained field sequential color wheel is presented. The design of a color wheel of maximum efficiency, the selection of spectral filters, and the design of a quiet, efficient wheel drive system are included. Design tradeoffs considered for each aspect of the modular assembly are discussed. Emphasis is placed on achieving a design which can be attached directly to an unmodified camera, thus permitting use of the assembly in evaluating various candidate camera and sensor designs. A technique is described which permits maintaining high optical efficiency with an unmodified camera. A motor synchronization system is developed which requires only the vertical synchronization signal as a reference frequency input. Equations and tradeoff curves are developed to permit optimizing the filter wheel aperture shapes for a variety of different design conditions.
Source record↗
Anamorphic lens for tracking system
Lens has 2:1 focal-length ratio, consists of three spherical and two cylindrical elements, and is 7.6 cm in length. When used in conjunction with image dissector tube, expected root-mean-square noise equivalent angle is approximately 8 arc seconds.
Burns, R. H.↗
Gravitational lens of the sun - Its potential for observations and communications over interstellar distances
The gravitational field of the sun acts as a spherical lens to magnify the intensity of radiation from a distant source along a semi-infinite focal line. A spacecraft anywhere on that line in principle could observe, eavesdrop, and communicate over interstellar distances, using equipment comparable in size and power with what is now used for interplanetary distances. If one neglects coronal effects, the maximum magnification factor for coherent radiation is inversely proportional to the wavelength, being 100 million at 1 millimeter. The principal difficulties are that the nearest point on the focal half-line is about 550 times the sun-earth distance, separate spacecraft would be needed to work with each stellar system of interest, and the solar corona would severely limit the intensity of coherent radiation while also restricting operations to relatively short wavelengths.
Eshleman, V. R.↗
Changes in "thermal lens" measure diffusivity
In an extension of "thermal lens" effect to new applications and better resolution, two laser beams combine to rapidly measure thermal diffusivity and other molecular dynamic properties. New double-beam technique handles very small samples unlike classical techniques for measuring diffusivity. It can be used for measurements on samples undergoing stress, making it applicable to data collection for structural engineering.
Gupta, A.↗
Ultrasonic imaging using trapped energy mode Fresnel lens transducers
Trapped-energy focusing transducers operating in the 2-5 MHz range have been fabricated by plating concentric rings of electrodes on a piezoelectric plate. The concentric ring structure acts as a Fresnel lens and can be used to obtain excellent lateral focusing of ultrasonic waves. The trapping is sufficiently strong to permit optimization of electrode spacings to suppress spurious virtual foci and ring sidelobes.
Das, P.↗
The triple quasar Q1115+080A, B, C - A quintuple gravitational lens image
Spectroscopy and direct imaging of Q1115+080A, B, C with a CCD camera support the hypothesis that they are gravitational images of a single object. Spectroscopy of the semiforbidden C III 1909-A emission line shows all the images to have identical spectra and redshifts (to within 100 km/s), except that B is slightly redder. Gravitational lens imaging by a massive spiral galaxy is investigated, and a quintuple image model resembling Q1115+080A, B, C is found. In this model, Q1115+080A is a highly magnified close pair of images oriented in the position angle 23 deg. An elongation Q1115+080A at this angle is seen in the CCD pictures.
Young, P.↗
Methane Detector With Plastic Fresnel Lens
Laser detector for natural gas leaks modified by substitution of molded plastic lens for spherical mirror. By measuring relative attenuation at two wavelengths, detector used to check for methane escaping from pipelines above or below ground and from landfill.
Grant, W. B.↗
Response characteristics of laser diffraction particle size analyzers - Optical sample volume extent and lens effects
The response characteristics of laser diffraction particle sizing instruments were studied theoretically and experimentally. In particular, the extent of optical sample volume and the effects of receiving lens properties were investigated in detail. The experimental work was performed with a particle size analyzer using a calibration reticle containing a two-dimensional array of opaque circular disks on a glass substrate. The calibration slide simulated the forward-scattering characteristics of a Rosin-Rammler droplet size distribution. The reticle was analyzed with collection lenses of 63 mm, 100 mm, and 300 mm focal lengths using scattering inversion software that determined best-fit Rosin-Rammler size distribution parameters. The data differed from the predicted response for the reticle by about 10 percent. A set of calibration factor for the detector elements was determined that corrected for the nonideal response of the instrument. The response of the instrument was also measured as a function of reticle position, and the results confirmed a theoretical optical sample volume model presented here.
Hirleman, E. D.↗
Gravitational lens effects of a cosmological density of compact objects
Amplification of quasar light by a cosmological density of compact objects causes significant effects on many quasars in magnitude-limited samples. For lens masses solar mass less than 100,000 solar mass the continuum would be amplified by a magnitude or more but the line emission would not. Examination of the UV selected sample of Marshall et al. (1983) gives limits to more than 90 percent statistical confidence of Omega(c) less than 0.1 for a mass between 200 and 100,000 solar mass, where Omega(c) is the mean density of objects of mass M relative to the closure density. Preliminary results from an X-ray selected sample may probe to more than 0.1 solar mass and give a value for Omega(c) of less than one. These limits indicate that the remnants of an early population of massive stars cannot make a cosmologically significant contribution to the mass density of the universe. On a separate topic, recent work on the enhanced surface density of quasars near galaxies due to lensing by stars in the galaxy halos is reviewed.
Canizares, C. R.↗
1300 + 361 A,B is not a gravitational lens
Spectroscopic observations toward 1300 + 361 B obtained at 320-940 nm using a double spectrograph with CCD detectors on the 5-m Hale telescope (resolution about 7 A at 470-940 nm and 10-12 A at 320-470 nm on April 4-5, 1984, are reported. Two objects with magnitude 20 and spectral characteristics resembling those of an interacting pair of metal-poor H II regions at redshift 0.107 are observed, separated by about 10.6 arcsec and with a velocity difference of less than 80 km/s. It is considered unlikely that these objects form a gravitational-lens system. The ratio of the dereddened flux of the 5007-A forbidden line of O III to that of H-beta is found to be 5.03 for 1300 + 361 A and 3.67 for 1300 + 361 B; the difference is attributed to the presence of star-forming regions in the interacting system.
Halpern, J. P.↗
Development of the Lens Antenna Deployment Demonstration (LADD) shuttle-attached flight experiment
The primary objective of the LADD Program is to develop a technology demonstration test article that can be used for both ground and flight tests to demonstrate the structural and mechanical feasibility and reliability of the single-axis roll-out space based radar (SBR) approach. As designed, the LADD will essentially be a generic strucutural experiment which incorporates all critical technology elements of the operational satellite and is applicable to a number of future antenna systems. However, to fully determine its design integrity for meeting the lens flatness and constant geometry requirements in a zero g environment under extreme thermal conditions, the LADD must be space flight tested. By accurately surveying the structure under varying conditions the membrane tolerance-holding capabilities of the structure will be demonstrated. The flight test will provide data to verify analytical tools used to predict thermal and structural behavior. Most important, the experiment will provide an initial indication of structural damping in a zero g vacuum environment. The recently completed Solar Array Flight Experiment (SAFE) showed orbital damping greater than that experienced during ground testing. From the experience and the information obtained from LADD it is hoped that designs can be confidently extrapolated to operational satellites with apertures in the 20 m by 60 m size range.
Hill, H.↗
40 Eridani and the gravitational lens effect
Observations covering a period of 20 years show that the large proper motion (4.08 arcsec/yr) of the nearly triple system 40 Eridani-ABC will cause its brightest member, A, to pass within 3 arcsec of a faint background star. The originally hoped-for primary gravitational lens effect will therefore not take place although a minor secondary effect may occur near the time of closest approach on June 1, 1987.
Feibelman, Walter A.↗