Journal articles: 'Telescopic lens'

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Horiuchi, Noriaki. "Telescopic contact lens." Nature Photonics 9, no. 10 (September 29, 2015): 631. http://dx.doi.org/10.1038/nphoton.2015.193.

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Il'inskii, R. E. "Telescopic gradient lens." Journal of Optical Technology 67, no. 6 (June 1, 2000): 580. http://dx.doi.org/10.1364/jot.67.000580.

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Arianpour, Ashkan, Glenn M. Schuster, Eric J. Tremblay, Igor Stamenov, Alex Groisman, Jerry Legerton, William Meyers, Goretty Alonso Amigo, and Joseph E. Ford. "Wearable telescopic contact lens." Applied Optics 54, no. 24 (August 11, 2015): 7195. http://dx.doi.org/10.1364/ao.54.007195.

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Tremblay, Eric J., Igor Stamenov, R. Dirk Beer, Ashkan Arianpour, and Joseph E. Ford. "Switchable telescopic contact lens." Optics Express 21, no. 13 (June 27, 2013): 15980. http://dx.doi.org/10.1364/oe.21.015980.

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Peli, Eli, and Fernando Vargas-Martín. "In-the-spectacle-lens telescopic device." Journal of Biomedical Optics 13, no. 3 (2008): 034027. http://dx.doi.org/10.1117/1.2940360.

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Lipshitz, Isaac, Anat Loewenstein, Meir Reingewirtz, and Moshe Laza. "An Intraocular Telescopic Lens for Macular Degeneration." Ophthalmic Surgery, Lasers and Imaging Retina 28, no. 6 (June 1997): 513–17. http://dx.doi.org/10.3928/1542-8877-19970601-14.

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Tsaplin, S. V., and S. A. Bolychev. "Investigation of thermal conditions of nanosatellite optoelectronic telescopic module for different modes of operation." VESTNIK of Samara University. Aerospace and Mechanical Engineering 18, no. 2 (July 2, 2019): 96–111. http://dx.doi.org/10.18287/2541-7533-2019-18-2-96-111.

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The problem of studying thermal conditions of the optoelectronic telescopic module of a nanosatellite under the influence of operating conditions is considered. To maintain optimal thermal conditions of the telescopic lens, a thermal control system based on electric heaters was chosen. Based on the three-dimensional model, the thermal regime of the lens is calculated taking into account the real operating conditions of the nanosatellite in its orbital motion. As a result of the calculation by the finite element method, the dynamics of the temperature fields of the lens was obtained for different modes of operation of the nanosatellite: access to the established thermal conditions, earth terrain survey in normal and extended modes. It is shown that in different modes of operation the thermal control system maintains a given temperature range of optical elements with moderate energy consumption and provides lens efficiency during the entire time of operation of the optoelectronic telescopic module of the nanosatellite.

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Marzo, Sam J., and Andrew J. Hotaling. "Trade-off between Airway Resistance and Optical Resolution in Pediatric Rigid Bronchoscopy." Annals of Otology, Rhinology & Laryngology 104, no. 4 (April 1995): 282–87. http://dx.doi.org/10.1177/000348949510400405.

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Contemporary pediatric rigid bronchoscopy reflects the culmination of years of work by prominent endoscopists aided by technical developments in optical physics and refinements in optical lens manufacturing. Improved neonatal and pediatric care has allowed survival of premature infants, many with bronchopulmonary diseases. Rigid bronchoscopy in these infants is demanding and has necessitated the development of miniaturized telescopic bronchoscopes. This study documents airway pressures through bronchoscopes with and without endoscopic telescopes, analyzes and quantitates optical resolution, discusses the trade-offs between these instruments in airway resistance and optical resolution, and makes recommendations regarding which combinations of endoscopes and bronchoscopes provide the best resistance and resolution profiles. We conclude that the size 1.9-mm endoscopic telescope provides the most favorable resistance and resolution profile for the size 2.5 to 3.0 bronchoscopes, the 2.8-mm telescope is ideal for the 3.5 bronchoscope, and the 4.0-mm telescope works best with the 4.0 and larger bronchoscopes. Furthermore, optical forceps and side-channel forceps used during bronchial foreign body removal cause little change in airway resistance.

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Agarwal, Amar, Isaac Lipshitz, Soosan Jacob, Mandeep Lamba, Rahul Tiwari, Divya A. Kumar, and Athiya Agarwal. "Mirror telescopic intraocular lens for age-related macular degeneration." Journal of Cataract & Refractive Surgery 34, no. 1 (January 2008): 87–94. http://dx.doi.org/10.1016/j.jcrs.2007.08.031.

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Tarkhanov, Vladimir Ivanovich. "Aplanatic and Telescopic Lens with a Radial Gradient of Refraction Index." Optics and Photonics Journal 03, no. 07 (2013): 351–59. http://dx.doi.org/10.4236/opj.2013.37055.

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Schuster, Glenn M., Ashkan Arianpour, Scott Cookson, Eric J. Tremblay, Igor Stamenov, Arthur Zhang, Lee Hendrik, et al. "Wearable Wink-controlled Telescopic Contact Lens with Liquid Crystal Shutter Glasses." Journal of Vision 16, no. 4 (February 12, 2016): 14. http://dx.doi.org/10.1167/16.4.4.

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LEWIS, HOWARD T. "Parameters of Contact Lens-Spectacle Telescopic Systems and Considerations in Prescribing." Optometry and Vision Science 63, no. 5 (May 1986): 387–91. http://dx.doi.org/10.1097/00006324-198605000-00012.

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LAVINSKY, J., G. TOMASETTO, and E. SOARES. "Use of a contact lens telescopic system in low vision patients." International Journal of Rehabilitation Research 24, no. 4 (December 2001): 337–40. http://dx.doi.org/10.1097/00004356-200112000-00012.

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Vincent, Stephen J. "The use of contact lens telescopic systems in low vision rehabilitation." Contact Lens and Anterior Eye 40, no. 3 (June 2017): 131–42. http://dx.doi.org/10.1016/j.clae.2017.03.002.

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Alió, Jorge L., Emilia M. Mulet, José Ma Ruiz-Moreno, Maria José Sanchez, and Ahmed Galal. "Intraocular telescopic lens evaluation in patients with age-related macular degeneration." Journal of Cataract & Refractive Surgery 30, no. 6 (June 2004): 1177–89. http://dx.doi.org/10.1016/j.jcrs.2003.10.038.

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Dag, Medine Yilmaz, Filiz Afrashi, Serhad Nalcaci, Jale Mentes, and Cezmi Akkin. "The efficacy of “IOL-Vip Revolution” telescopic intraocular lens in age-related macular degeneration cases with senile cataract." European Journal of Ophthalmology 29, no. 6 (October 3, 2018): 615–20. http://dx.doi.org/10.1177/1120672118803831.

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Purpose: To evaluate the efficacy of the IOL-Vip Revolution telescopic intraocular lens in age-related macular degeneration patients. Methods: A total of 13 eyes of 12 age-related macular degeneration patients with senile cataract were enrolled. Selection of the patients was done by means of a low vision diagnostic and rehabilitative program (IOL-Vip software) that evaluates residual visual function. After standard phacoemulsification surgery, the incision site was enlarged and the IOL-Vip Revolution system was implanted in the capsular bag. The outcome measures were best corrected visual acuity, contrast sensitivity, anterior chamber depth, endothelial cell density, central corneal thickness, and quality-of-life questionnaire. Results: The mean age of the subjects was 72.3 ± 8.5 years. The mean positive power of the intraocular lens was 59 ± 2 D and the negative intraocular lens power was standard (–46 D). Pre- and postoperative best corrected visual acuity were 1.08 ± 0.14 and 0.81 ± 0.16 logMAR in the operated eye and 1.13 ± 0.36 and 1.01 ± 0.40 logMAR in the unoperated eye, respectively. The best corrected visual acuity was increased significantly in both operated and unoperated eyes (p = 0.005 and 0.021, respectively). Quality of life and anterior chamber depth increased significantly (p = 0.018 and 0.008, respectively), while endothelial cell density decreased (p = 0.002). No significant differences were detected in central corneal thickness or contrast sensitivity (p = 0.133 and 0.684, respectively). Conclusion: The results showed that IOL-Vip Revolution telescopic intraocular lens is a promising treatment option in age-related macular degeneration patients. The rehabilitation program may have an important role in the restored clinical results, which also provided visual improvement in the unoperated eyes.

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Yang, Bin, Yuan Wang, and Wen Bo He. "Application of Micro-PIV on the Microscale Flow and a Modified System Based on Ordinary 2-D PIV." Advanced Materials Research 346 (September 2011): 657–63. http://dx.doi.org/10.4028/www.scientific.net/amr.346.657.

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This paper briefly presents the working principle of micro-PIV (Particle Imaging Velocimetry) and its development and application on the microscale flow. Compared with ordinary PIV, micro-PIV has much higher spatial resolution. In addition, the adoption of fluorescent tracer and filter lens could enable flow field near wall surface to be measured. In view of the ordinary 2-D PIVs have been widespread among the scientific research institution related on fluid flow, the way that an ordinary 2-D PIV was modified to enable measurement of microscale flow was discussed in the paper. The extra elements of microscope objective lens, relay mirror, filter lens and telescopic focusing barrel are necessary. Some experiment results of the flow in microscale channels have been introduced to verify the availability of the modified PIV system. It could be found from the experimental results that the modified PIV system could be feasible and reliable for measuring micro-scale flows.

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Dunham, Michael E., and Rosalee N. Wolf. "Visualizing the Pediatric Airway: Three-Dimensional Modeling of Endoscopic Images." Annals of Otology, Rhinology & Laryngology 105, no. 1 (January 1996): 12–17. http://dx.doi.org/10.1177/000348949610500103.

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Three-dimensional reconstruction of medical images has emerged as an important visualization tool for studying complex anatomy. These tools have found important applications in neurology and plastic surgery using computed tomography (CT) and magnetic resonance imaging (MRI) data. However, CT and MRI do not sufficiently delineate lesions of the pediatric airway. Inspection through the rod lens telescope remains the standard diagnostic method. A video recording of an endoscopic procedure is essentially a sequence of two-dimensional images captured as the telescope traverses the airway lumen. Using digitized endoscopic video recordings and computer graphics reconstruction techniques, we have developed a preliminary three-dimensional modeling system for the pediatric airway. A series of normal and abnormal telescopic airway examinations were video recorded. Serial sections were obtained by digitizing the video images at uniform intervals as the scope traversed the airway lumen between the vocal folds and the carina. The digitized images were calibrated and used to reconstruct the airway lumen in three dimensions. Classifying airway abnormalities according to the minimal cross-sectional area or with descriptive terms can be subjective and dependent on the endoscopist's observational skills. We hope that this preliminary work will lead to more precise and understandable methods for representing complex airway lesions.

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Jirásková, N., P. Rozsíval, and A. Kohout. "A Survey of Intraocular Lens Explantation: A Retrospective Analysis of 23 IOLs Explanted during 2005." European Journal of Ophthalmology 17, no. 4 (July 2007): 579–87. http://dx.doi.org/10.1177/112067210701700416.

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Purpose To evaluate the indications, lens styles, perioperative findings, and results of intraocular lens (IOL) explantation or exchange performed in the authors department in 2005. Methods The retrospective analysis comprised 22 patients (23 eyes). Twenty-one eyes had previous phacoemulsification and IOL implantation, one eye secondary aphakic IOL, and one eye phakic IOL implantation. The indications for IOL explantation/exchange and perioperative complications were evaluated. The best-corrected visual acuity (BCVA) before and after surgery was compared. Results Time from initial surgery to explantation/exchange varied from 1 to 121 months, median value was 46 months. The IOLs were explanted using local anesthesia and in 21 eyes replaced with new lens. Indications for IOL removal were opacification of the IOL in 12 eyes, malposition of the IOL in 5 eyes, postoperative refractive error in 2 eyes, recurrent toxic anterior segment syndrome in 1 eye, pseudophakic dysphotopsia in 1 eye, endothelial cell loss in phakic anterior chamber IOL in 1 eye, and visual discomfort with intraocular telescopic lens in 1 eye. The mean BCVA (decimal scale) before and after IOL explantation/exchange was 0.562±0.279 and 0.627±0.276, respectively. There was no significant difference in visual acuity before and after IOL exchange (Wilcoxon test). Conclusions The most frequent indications for IOL explantation/exchange were opacification of the IOL and IOL malposition. Surgeries were uneventful in most cases. Final visual results have been largely good. Long-term follow-up of patients with various types of IOLs should be maintained.

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Ward, Robert F. "Treatment of Tracheal and Endobronchial Lesions with the Potassium Titanyl Phosphate Laser." Annals of Otology, Rhinology & Laryngology 101, no. 3 (March 1992): 205–8. http://dx.doi.org/10.1177/000348949210100302.

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Lower tracheal and endobronchial lesions represent a difficult management problem. While there has been some success in the treatment of these lesions with the carbon dioxide laser, the limitations of its delivery system have restricted its use in infants and neonates. The potassium titanyl phosphate (KTP) laser, transmitted via a flexible quartz fiber, can be precisely manipulated even through rigid pediatric bronchoscopes as small as 3.0 mm. In addition, the Hopkins telescopic lens may be used to improve visualization and control. We report our experience using the KTP laser to treat 15 pediatric patients with tracheal and endobronchial lesions. The nature of the lesions, the details of the technique, and the results are presented.

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Moncrieff, Lilian. "Law, Scale, Anti-zooming, and Corporate Short-termism." Law, Culture and the Humanities 16, no. 1 (June 27, 2016): 103–26. http://dx.doi.org/10.1177/1743872116654670.

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This article uses “Contact,” an art installation by Olafur Eliasson, and “anti-zoom,” an essay by Bruno Latour to reimagine the problem of corporate short-termism. It investigates what it means to propose, under the gaze of law, that directors and investors look to the “long-term” when pursuing corporate purposes. The article contests that it is possible to zoom, as if using a telescopic lens, between the demands of different time frames. It is only after an extended amount of “contact” that one is able to plot the relation of the short to the long term and make sense of it, a finding that problematizes the corporate self-governance of time. A way forward is imagined that makes the thesis of anti-zoom fit for renovating corporate law.

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Land, Michael F. "A note on the elongated eye of the octopus Vitreledonella richardi." Journal of the Marine Biological Association of the United Kingdom 72, no. 1 (February 1992): 89–92. http://dx.doi.org/10.1017/s0025315400048803.

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The elongated eye of Vitreledonella richardi is described from two specimens caught at 200 m in the North Atlantic. It is shown that the cylindrical shape, with the lens placed centrally, results in a reduced field of view in the horizontal plane. It is argued that the unusual shape is an adaptation which minimises the silhouette of the eye as seen from below, and is part of the animal's camouflage strategy.IntroductionThe majority of fish and cephalopods have two hemispherical eyes, each of which has a field covering roughly the 180° on one side of the animal (Walls, 1942; Packard, 1972). The commonest exceptions to this rule are animals with so-called ‘telescopic’ eyes, found in many species of deepsea fish (e.g. Benthalbella, Argyropelecus, Opisthoproctus, Scopelarchus, see Marshall, 1954; Locket, 1977) and some cephalopods (Amphitretus, see Chun, 1915; Histioteuthis sp., see Young, 1975a). These eyes are tubular, with the lens at the open end of the tube, and a retina with a reduced field of view at the other. The eyes usually point upwards, and it is generally agreed that their shape is determined by the need to concentrate sensitivity and resolution into the rather narrow field above the animal where the residual daylight is still adequate for visual detection. It is 200 times darker in the downward direction (Denton, 1990), and so there must be some depth at which upward vision works, but downward vision does not. These are not the only kind of tubular eyes, however. In some cephalopods, but not to my knowledge in any fish, there are eyes of tubular appearance but with the lens not at the end, but in the centre of the tube (Figure 1).

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Jahan-Tigh, Richard R., Garrett M. Chinn, and Ronald P. Rapini. "A Comparative Study Between Smartphone-Based Microscopy and Conventional Light Microscopy in 1021 Dermatopathology Specimens." Archives of Pathology & Laboratory Medicine 140, no. 1 (January 1, 2016): 86–90. http://dx.doi.org/10.5858/arpa.2014-0593-oa.

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Context The incorporation of high-resolution cameras into smartphones has allowed for a variety of medical applications including the use of lens attachments that provide telescopic, macroscopic, and dermatoscopic data, but the feasibility and performance characteristics of such a platform for use in dermatopathology have not been described. Objective To determine the diagnostic performance of a smartphone microscope compared to traditional light microscopy in dermatopathology specimens. Design A simple smartphone microscope constructed with a 3-mm ball lens was used to prospectively evaluate 1021 consecutive dermatopathology cases in a blinded fashion. Referred, consecutive specimens from the community were evaluated at a single university hospital. The performance characteristics of the smartphone platform were calculated by using conventional light microscopy as the gold standard. The sensitivity and specificity for the diagnosis of melanoma, nonmelanoma skin cancers, and other miscellaneous conditions by the phone microscopy platform, as compared with traditional light microscopy, were calculated. Results For basal cell carcinoma (n = 136), the sensitivity and specificity of smartphone microscopy were 95.6% and 98.1%, respectively. The sensitivity and specificity for squamous cell carcinoma (n = 94) were 89.4% and 97.3%, respectively. The lowest sensitivity was found in melanoma (n = 15) at 60%, although the specificity was high at 99.1%. The accuracy of diagnosis of inflammatory conditions and other neoplasms was variable. Conclusions Mobile phone–based microscopy has excellent performance characteristics for the inexpensive diagnosis of nonmelanoma skin cancers in a setting where a traditional microscope is not available.

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Agrawal, A., N. E. Deveneau, and S. L. Francis. "Vaginal Hysterectomy, Modified Mayo McCalls Suspension with the Assistance of the Magrina Vaginal Bookwalter (R): A Unique Surgeon’s Perspective Using a Telescopic Lens." Journal of Minimally Invasive Gynecology 21, no. 6 (November 2014): S8. http://dx.doi.org/10.1016/j.jmig.2014.08.043.

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Fiodоrtsev, R. V., E. A. Metelskaya, V. A. Marchik, A. V. Kuznetsov, and A. E. Makarevich. "Method for Increasing of Lens Gluing Technological Process Efficiency and a Reliable Evaluation of Output Controlled Parameters." Devices and Methods of Measurements 13, no. 1 (April 4, 2022): 50–59. http://dx.doi.org/10.21122/2220-9506-2022-13-1-50-59.

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The use of glued lens components in optical devices improves the image quality of telescopic and photographic lenses or inverting systems by eliminating a number of aberrations, and also reduces light losses in the optical system of the device. The traditional production process of lenses gluing involves the sequential execution of a set of technological operations and takes a significant period of time. The purpose of the research was to improve the accuracy and productivity of the technological process of lenses gluing by improving the optical system of the control and measuring device and automating the operation of lenses optical axes combining by introducing an electronic reference system and mechanisms for micro-movements of optical parts.A technique is proposed for centering of two and three-component optical blocks by an autocollimation flare which provides a matching accuracy of less than 0.5 μm. The possibility of constructive modernization of the classic ST-41 autocollimation microscope with parallel separation of the displayed output information in the visual and television channels is shown. An automated system for controlling of the process of convergence of autocollimation points in the device is proposed. Using software methods an electronic grid template is formed on the monitor screen, onto which images of autocollimation points are projected. The decentering value 2Δe is determined and a corrective control voltage is applied to three stepper motors and pushers for transverse movement of the glued optical part.Specialized software has been developed for automatically bringing the position of the autocollimating crosshair to the center of the measuring scale of the grid based on a combination of two methods of “least squares” and “successive approximation”. Compliance with a number of technological transitions and the accompanying control of geometric parameters make it possible to achieve greater accuracy in determining the eccentricity of the crosshairs of the aligned optical axes of the glued lenses.

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Misra, Anupam K., Tayro E. Acosta-Maeda, John N. Porter, Genesis Berlanga, Dalton Muchow, Shiv K. Sharma, and Brian Chee. "A Two Components Approach for Long Range Remote Raman and Laser-Induced Breakdown (LIBS) Spectroscopy Using Low Laser Pulse Energy." Applied Spectroscopy 73, no. 3 (November 20, 2018): 320–28. http://dx.doi.org/10.1177/0003702818812144.

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The remote detection of chemicals using remote Raman spectroscopy and laser-induced breakdown spectroscopy (LIBS) is highly desirable for homeland security and NASA planetary exploration programs. We recently demonstrated Raman spectra with high signal-to-noise ratio of various materials from a 430 m distance during daylight with detection times of 1–10 s, utilizing a 203 mm diameter telescopic remote Raman system and 100 mJ/pulse laser energy at 532 nm for excitation. In this research effort, we describe a simple two-components approach that helps to obtain remote Raman and LIBS spectra of targets at distance of 246 m with 3 mJ/pulse in daytime. The two components of the method are: (1) a small spectroscopy system utilizing 76 mm diameter collection optics; and (2) a small remote lens near the target. Remote Raman spectra of various chemicals are presented here with detection time of 1 s. Remote LIBS spectra of minerals using single laser pulse of 3 mJ/pulse energy from a distance of 246 m are also presented. This research work demonstrates a simple approach that significantly improves remote Raman and LIBS capabilities for long range chemical detection with compact low laser power Raman and LIBS systems.

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Perfetti, L., F. Fassi, and C. Rossi. "FISHEYE PHOTOGRAMMETRY TO GENERATE LOW-COST DTMS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-2/W17 (November 29, 2019): 257–63. http://dx.doi.org/10.5194/isprs-archives-xlii-2-w17-257-2019.

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Abstract. In the archaeological practice, Digital Terrain Models (DTMs) and Digital Surface Models (DSMs) may be used to represent spatial information about the site by conveying information such as differences in levels, morphology of the terrain and movements of volumes during the excavation. Nowadays DTMs and DSMs can be easily obtained by image-based matching using low altitude aerial dataset acquired from a digital camera by means of a lifting device. In recent years, the spread of commercial multi-rotor unmanned aerial vehicles and their decreasing cost made low-altitude aerial photography even easier than before, where balloons, kites and telescopic masts would have been used instead. However, the use of drones is often forbidden by law, especially in the archaeological areas, and therefore a more traditional approach must to be adopted instead.This paper presents two different approaches adopted on the field to acquire the DTM of an archaeological excavation: the use of a pole held by a chest harness to lift a camera up to 3.5 m height fitted with a 20 mm wide angle lens; and a second solution that exploits ground-based fisheye photogrammetry. In general, an image network acquired from ground level is challenging due to: i) the poor coverage that can be obtained on the ground, ii) the large number of images that are required to cover large areas and consequently iii) the longer elaboration time that is required to process the data. The fisheye approach, however, proved to be more effective thanks to the more robust image network resulting both from the wider field of view and from the possibility to handle large datasets by downsampling the images and still retrieving strong key points. The main difference with the first system is that the monotonous images acquired by the 20 mm lens, very plain in texture, require working at full resolution in order to distinguish valid features in the sand.The final product of the tests carried out along this line in 2019 at Saqqara (Egypt) is a comprehensive DSM of the entire archaeological site with an accuracy of ~3 cm.

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Salukvadze, G. N. "Astrometric Characteristics of the Abastumani Astrophysical Observatory 125 cm Reflector (AZT-11) of Ritchey-Cretien Optical System." Symposium - International Astronomical Union 109 (1986): 289–92. http://dx.doi.org/10.1017/s0074180900076701.

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Quite a number of instances are known when Schmidt, mirror-lens system telescopes and generally reflectors are used for solving the problems of photographic astrometry.This paper describes the use of the Ritchey-Cretien telescope (AZT-11) at the Abastumani Astrophysical Observatory for determining relative positions of the members of multiple systems.

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Ma, Chen Hao, Yue Gang Fu, Chun Hua Luo, Dong Hu Zhang, and Yan Liu. "Design of Digital Binoculars Image Stabilizing Optical System." Key Engineering Materials 552 (May 2013): 85–92. http://dx.doi.org/10.4028/www.scientific.net/kem.552.85.

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Digital binoculars is the combination of digital cameras and telescopes, it not only can observe the details of the long distance target but also can record it. The field of view between photographic field lens and telescope system is the same. This paper designs the telescope system on basis of the theory of dynamic optics. The system works in visual light waveband. The field of view is , the magnification is eight and the entrance pupil diameter is 32mm. prism is selected as the image rotation prism and image stabilization prism. In order to obtain clear images in a dynamic circumstance, we utilize the rotation theorem of prism to analyze the relation between jitter compensated lens and luminous beam angle. We can calculate the position of compensated lens. So it can achieve the jitter compensation. Finally, this paper takes an application as an example. If the jittered angle is , the displacement of pixel is calculated to 1.061mm. The displacement of the compensated lens is 2.84mm. At the same time, the light still arrives to the eyepiece by the original track. So image stabilization is relative to the reference coordinate, as a result we can get the stable image.

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Sohib, Ahmad, Niko Danusaid, Astri Sawitri, Bebeh Wahid Nuryadin, and Rena Denya Agustina. "Low cost digitalization of observation telescope by utilizing smartphone." MATEC Web of Conferences 197 (2018): 02002. http://dx.doi.org/10.1051/matecconf/201819702002.

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Digitalization of telescopes used as learning media observation of the object is quite effective. However, the cost of operating this system becomes one of the obstacles. The approach to overcome the obstacle can be conducted by utilization of the present technology such as smartphone. Physical experiments have been conducted on the design of digitalization of the starter binoculars interfacing to Personal Computer (PC) using a smartphone. This experiment is aimed to design a more efficient digitalization of telescope observations. Smartphone stative is made in such a way that the camera in the right position on the telescope lens. Data retrieval is taken by a smartphone camera and ASI120MC camera as a comparison parameter. The data will be sent to the PC via an application installed both on smartphone and PC attributed by Bluetooth network. The camera is supported with a camera stative to keep it apart from binoculars. The observations obtained from this system is an interpretation between the camera on the telescope and PC. Such interpretations may produce images or videos observed by telescopes. This design can simplify the interfacing of telescope resulting good enough photo quality.

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Kim, Dae Wook, Christopher K. Walker, Dániel Apai, Tom D. Milster, Yuzuru Takashima, Glenn Schneider, Rongguang Liang, et al. "Disruptive space telescope concepts, designs, and developments: OASIS and Nautilus -INVITED." EPJ Web of Conferences 238 (2020): 06001. http://dx.doi.org/10.1051/epjconf/202023806001.

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Two disruptive space telescope concepts are being designed and developed at the University of Arizona; these are the 20-meter OASIS (Orbiting Astronomical Satellite for Investigating Stellar Systems) and 8.5-meter Nautilus. OASIS combines break-through inflatable aperture and adaptive optics techniques to realize the dream of a 20+ meter class spaceborne terahertz/far-infrared telescope. In the Nautilus visible/near-infrared telescope concept, conventional primary mirrors are replaced by an ~8.5-meter MODE (Multi-order diffractive engineered) lens with 10 times lower areal density and up to 100 times lower mis-alignment sensitivity over traditional systems, enabling large-diameter optical space telescopes. The OASIS and Nautilus concepts have the potential to greatly reduce mission costs and risks compared to the current state of the art.

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Michaelis, M. M., C. A. Dempers, M. Kosch, A. Prause, M. Notcutt, P. F. Cunningham, and J. A. Waltham. "A gas-lens telescope." Nature 353, no. 6344 (October 1991): 547–48. http://dx.doi.org/10.1038/353547a0.

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Czekalski, Stanisław. "Talbotowski paradygmat wizualności fotografii." Artium Quaestiones, no. 28 (May 22, 2018): 5–32. http://dx.doi.org/10.14746/aq.2017.28.1.

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The concept of visuality proposed by Norman Bryson, which refers to conscious perception determined by a system of concepts and knowledge of the visible, is related in the paper to the relationship between two kinds and ideas of photography, introduced respectively by Louis J. Daguerre and William H. Fox Talbot. The discourse about daguerrotypy stresses the quasi-telescopic properties of the picture whose visually ungraspable surface triggers an effect of reaching with the eye far beyond it toward even the farthest details, invisible without a looking glass but still clearly visible in the picture. In response to this feature, Talbot connected the photographic picture primarily with the effects of transferring the relations of shadow and light to contrast on the surface of photosensitive paper. He referred the “photogenic drawing” to a tradition older than the Albertian paradigm of the illusion of perspective adopted by Daguerre in his famous views of the streets of Paris from the window. His technique, called “skiagraphy,” Talbot associated with an ancient legend about the origin of drawing as the art of fixing shadows on a flat surface. His photographs of Lacock Abbey windows were a paradigmatic example that determined the understanding of each photo on the level of its basic self-reflexive content: in the first place, the photographic picture shows how reality before the camera lens projects its “skiagraphic” drawing – a “stamp,” as it were – on the paper surface, and how the forms of objects are reduced to that surface and grasped on it. In his Pencil of Nature, Talbot connected photographic pictures with text, determining the visual status of print photography as replica – both repetition of the highly appreciated daguerrotypy, and a rival response to it, showing the advantages of Calotypy based on the visible proximity of the picture and the surface. Thanks to the properties of Calotypy, precise “fixing of shadows” allows one to arrest despite the flow of time and fix in a visual structure what is the most volatile and changeable.

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Yuan, Xiangyan, Xiangqun Cui, Ding-qiang Su, Yongtian Zhu, Lifan Wang, Bozhong Gu, Xuefei Gong, and Xinnan Li. "Preliminary design of the Kunlun Dark Universe Survey Telescope (KDUST)." Proceedings of the International Astronomical Union 8, S288 (August 2012): 271–74. http://dx.doi.org/10.1017/s1743921312016997.

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AbstractFrom theoretical analysis and site testing work for 4 years on Dome A, Antarctica, we can reasonably predict that it is a very good astronomical site, as good as or even better than Dome C and suitable for observations ranging from optical to infrared & sub-mm wavelengths. After the Chinese Small Telescope ARray (CSTAR), which was composed of four small fixed telescopes with diameter of 145mm and the three Antarctic Survey Telescopes (AST3) with 500mm entrance diameter, the Kunlun Dark Universe Survey Telescope (KDUST) with diameter of 2.5m is proposed. KDUST will adopt an innovative optical system which can deliver very good image quality over a 2 square degree flat field of view. Some other features are: a fixed focus suitable for different instruments, active optics for miscollimation correction, a lens-prisms that can be used as an atmospheric dispersion corrector or as a very low-dispersion spectrometer when moved in / out of the main optical path without changing the performance of the system, and a compact structure to make easier transportation to Dome A. KDUST will be mounted on a tower with height 15m in order to make a full use of the superb free atmospheric seeing.

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Myers, Steven T. "1608+656: A Quadruple Lens System Found In The CLASS Gravitational Lens Survey." Symposium - International Astronomical Union 173 (1996): 317–22. http://dx.doi.org/10.1017/s0074180900231677.

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The first phase of a large gravitational lens survey using the Very Large Array at a wavelength of 3.6 cm has been completed, yielding images for 3258 radio sources. The Cosmic Lens All-Sky Survey, or CLASS, is designed to locate gravitational lens systems consisting of multiply-imaged compact components with separations > 0.″2. From this first phase has come the discovery of 1608+656, a quadruply-imaged object with maximum separation of 2.″1. Images from the Palomar 5-m and Keck 10-m telescopes show the lensed images and the lensing galaxy. An optical spectrum obtained with the Palomar 5-m Telescope indicates a redshift of z = 0.63 for the lensing galaxy, and a newly-obtained Palomar spectrum indicates a redshift of z = 1.39 for the lensed source, which appears to be a galaxy. A simple single-galaxy lens model derived from the radio image reproduces the observed configuration and relative fluxes of the images, as well as the position, shape, and orientation of the lensing galaxy. Because a simple mass model is able to fit the observations, we argue that this lens system is promising for determining H0. CLASS has also yielded the new double image lens system 1600+434. The second phase of the survey is scheduled for August and September 1995 on the VLA, and should yield images for an additional 5000+ targets, bringing the CLASS total to over 8000.

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Surdej, J., C. Delacroix, P. Coleman, M. Dominik, S. Habraken, C. Hanot, H. Le Coroller, et al. "THE OPTIMAL GRAVITATIONAL LENS TELESCOPE." Astronomical Journal 139, no. 5 (April 8, 2010): 1935–41. http://dx.doi.org/10.1088/0004-6256/139/5/1935.

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Webster, R. L. "Imaging with a Gravitational Lens." Symposium - International Astronomical Union 158 (1994): 451–56. http://dx.doi.org/10.1017/s0074180900108174.

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The basic ideas of gravitational microlensing are discussed. Particular attention is given to the use of a gravitational lens as a (non-standard) telescope, to probe the very small scale structure of extragalactic sources. The recovery of information from a gravitational lens telescope is discussed, as well as the unique contribution which can be made by imaging with a gravitational telescope.

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Magro, Daniel, Kristian Zarb Adami, Andrea DeMarco, Simone Riggi, and Eva Sciacca. "A comparative study of convolutional neural networks for the detection of strong gravitational lensing." Monthly Notices of the Royal Astronomical Society 505, no. 4 (June 9, 2021): 6155–65. http://dx.doi.org/10.1093/mnras/stab1635.

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ABSTRACT As we enter the era of large-scale imaging surveys with the upcoming telescopes such as the Large Synoptic Survey Telescope (LSST) and the Square Kilometre Array (SKA), it is envisaged that the number of known strong gravitational lensing systems will increase dramatically. However, these events are still very rare and require the efficient processing of millions of images. In order to tackle this image processing problem, we present machine learning techniques and apply them to the gravitational lens finding challenge. The convolutional neural networks (CNNs) presented here have been reimplemented within a new, modular, and extendable framework, Lens EXtrActor CaTania University of Malta (LEXACTUM). We report an area under the curve (AUC) of 0.9343 and 0.9870, and an execution time of 0.0061 and 0.0594 s per image, for the Space and Ground data sets, respectively, showing that the results obtained by CNNs are very competitive with conventional methods (such as visual inspection and arc finders) for detecting gravitational lenses.

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Yan, Shi, and Wei Zhu. "Measuring Microlensing Parallax via Simultaneous Observations from Chinese Space Station Telescope and Roman Telescope." Research in Astronomy and Astrophysics 22, no. 2 (February 1, 2022): 025006. http://dx.doi.org/10.1088/1674-4527/ac3c44.

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Abstract Simultaneous observations from two spatially well-separated telescopes can lead to measurements of the microlensing parallax parameter, an important quantity toward the determinations of the lens mass. The separation between Earth and Sun–Earth L2 point, ∼0.01 au, is ideal for parallax measurements of short and ultra-short (∼1 hr to 10 days) microlensing events, which are candidates of free-floating planet (FFP) events. In this work, we study the potential of doing so in the context of two proposed space-based missions, the Chinese Space Station Telescope (CSST) in a low-Earth orbit (LEO) and the Nancy Grace Roman Space Telescope (Roman) at L2. We show that joint observations of the two can directly measure the microlensing parallax of nearly all FFP events with timescales t E ≲ 10 days as well as planetary (and stellar binary) events that show caustic crossing features. The potential of using CSST alone in measuring microlensing parallax is also discussed.

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Woods, Robert O. "Clears Glass." Mechanical Engineering 128, no. 10 (October 1, 2006): 38–41. http://dx.doi.org/10.1115/1.2006-oct-4.

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This paper describes the progress made in lens making for telescopes. The use of rotating equipment was an important innovation in lens making, although it is possible to grind lenses entirely by hand. After grinding, the lens was polished, sometimes using the same lap that had been used to shape it. It required preparing the lap surface to remove roughness. In some cases, it was done by overlaying the surface of the lap with a specially prepared paper. Pitch was poured on the lens surface and, when it hardened, was removed, creating a tool exactly matching the curvature of the lens. When it became possible to make generalizations about the performance of telescopes, it became obvious that the spherical aberration due to the shape of simple lenses was a factor that limited optical quality. The vast majority of amateur-made telescopes are reflectors.

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Bakos, Gáspár Á. "RTLinux Driven Hungarian Automated Telescope for All Sky Monitoring." International Astronomical Union Colloquium 183 (2001): 59–64. http://dx.doi.org/10.1017/s0252921100078611.

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AbstractMassive variability searches initiated the design of HAT (Hungarian Automated Telescope), an autonomous observatory. HAT consists of a horseshoe mount similar to the one used in the Automated All Sky Survey (ASAS, Pojmański 1997), a clamshell dome with various utilities, a telephoto lens and a CCD. Expensive hardware elements have been substituted by software running under Realtime Linux: a multitask operating system which can handle processes in real time. A virtual observer – modeled as a finite state machine – is responsible for managing the observatory. The modular structure allows of running virtually any kind of observing program for small telescopes. We describe technical aspects, as well as present test results carried out by HAT1 (Budapest).

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Chirivì, G., A. Yıldırım, S. H. Suyu, and A. Halkola. "Gravitational Lensing and Dynamics (GLaD): combined analysis to unveil properties of high-redshift galaxies." Astronomy & Astrophysics 643 (November 2020): A135. http://dx.doi.org/10.1051/0004-6361/202037929.

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The dynamical modelling of integral field unit (IFU) stellar kinematics is a powerful tool to unveil the dynamical structure and mass build-up of galaxies in the local Universe, while gravitational lensing is nature’s cosmic telescope to explore the properties of galaxies beyond the local Universe. We present a new approach, which unifies dynamical modelling of galaxies with the magnification power of strong gravitational lensing, to reconstruct the structural and dynamical properties of high-redshift galaxies. By means of axisymmetric Jeans modelling, we create a dynamical model of the source galaxy, assuming a surface brightness and surface mass density profile. We then predict how the source’s surface brightness and kinematics would look when lensed by the foreground mass distribution and compare with the mock observed arcs of strong gravitational lensing systems. For demonstration purposes, we created and also analysed mock data of the strong lensing system RX J1131−1231. By modelling both the lens and source, we recover the dynamical mass within the effective radius of strongly lensed high-redshift sources within 5% uncertainty, and we improve the constraints on the lens mass parameters by up to 50%. This machinery is particularly well-suited for future observations from large segmented-mirror telescopes, such as the James Webb Space Telescope, which will yield high sensitivity and angular-resolution IFU data for studies on distant and faint galaxies.

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TEMEL, AHMET, TAYFUN BAVBEK, and AYFER KANPOLAT. "Clinical application of contact lens telescopes." International Journal of Rehabilitation Research 16, no. 2 (June 1993): 148–50. http://dx.doi.org/10.1097/00004356-199306000-00007.

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Yıldırım, Akın, Sherry H. Suyu, and Aleksi Halkola. "Time-delay cosmographic forecasts with strong lensing and JWST stellar kinematics." Monthly Notices of the Royal Astronomical Society 493, no. 4 (February 27, 2020): 4783–807. http://dx.doi.org/10.1093/mnras/staa498.

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ABSTRACT We present a joint strong lensing and stellar dynamical framework for future time-delay cosmography purposes. Based on a pixelated source reconstruction and the axisymmetric Jeans equations, we are capable of constraining cosmological distances and hence the current expansion rate of the Universe (H0) to the few per cent level per lens, when high signal-to-noise integral field unit (IFU) observations from the next generation of telescopes become available. For illustrating the power of this method, we mock up IFU stellar kinematic data of the prominent lens system RXJ1131−1231, given the specifications of the James Webb Space Telescope. Our analysis shows that the time-delay distance (DΔt) can be constrained with 3.1 per cent uncertainty at best, if future IFU stellar kinematics are included in the fit and if the set of candidate model parametrizations contains the true lens potential. These constraints would translate to a 3.2 per cent precision measurement on H0 in flat ΛCDM cosmology from the single lens RXJ1131−1231, and can be expected to yield an H0 measure with ≤2.0 per cent uncertainty, if similar gains in precision can be reached for two additional lens systems. Moreover, the angular diameter distance (Dd) to RXJ1131−1231 can be constrained with 2.4 per cent precision, providing two distance measurements from a single lens system, which is extremely powerful to further constrain the matter density (Ωm). The measurement accuracy of Dd, however, is highly sensitive to any systematics in the measurement of the stellar kinematics. For both distance measurements, we strongly advise to probe a large set of physically motivated lens potentials in the future, to minimize the systematic errors associated with the lens mass parametrization.

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Davidson, Michael W. "Pioneers in Optics: Giovanni Battista Amici and Girolamo Cardano." Microscopy Today 18, no. 3 (May 2010): 50–52. http://dx.doi.org/10.1017/s1551929510000295.

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Giovanni Amici was an Italian microscopist, astronomer, optical instrument designer, and botanist who is best known as the achromatic lens inventor. He also designed reflecting telescopes and introduced a lens for the inspection of an objective's rear focal plane, termed the Amici-Bertrand lens. Aditionally, in 1850 he invented the water immersion lens.

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Ohmori, H., W. Lin, S. Yin, Shinya Morita, Y. Uehara, T. Maihara, F. Iwamuro, and D. Mochida. "ELID Grinding Characterization of Large Schmidt Lens for Large Telescope(Nanoprecision Elid-grinding (continued))." Proceedings of International Conference on Leading Edge Manufacturing in 21st century : LEM21 2005.2 (2005): 715–20. http://dx.doi.org/10.1299/jsmelem.2005.2.715.

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Michaelis, M. M., P. F. Cunningham, R. S. Cazalet, J. A. Waltham, and M. Notcutt. "Gas lens applications." Laser and Particle Beams 9, no. 2 (June 1991): 641–51. http://dx.doi.org/10.1017/s0263034600003645.

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Various gas lenses are briefly reviewed, together with their imperfections. We discuss the applicability of these lenses as objectives for telescopes and as the final focusing element of high-power laser systems: cw lasers in industry and pulsed lasers for plasma research. A novel phase conjugate experiment employing a gas lens is described. Pulsed gas lenses are proposed as a solution to the problems of high laser fluence and radiation damage in post-break-even fusion experiments.

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Janeček, Petr, Jan Ebr, Jakub Juryšek, Michael Prouza, Jiří Blažek, Petr Trávníček, Dušan Mandát, et al. "FRAM telescopes and their measurements of aerosol content at the Pierre Auger Observatory and at future sites of the Cherenkov Telescope Array." EPJ Web of Conferences 197 (2019): 02008. http://dx.doi.org/10.1051/epjconf/201919702008.

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A FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope is a system of a robotic mount, a large-format CCD camera and a fast telephoto lens that can be used for atmospheric monitoring at any site when information about the atmospheric transparency is required with high spatial or temporal resolution and where continuous use of laser-based methods for this purpose would interfere with other observations. The original FRAM has been operated at the Pierre Auger Observatory in Argentina for more than a decade, while three more FRAMs are foreseen to be used by the Cherenkov Telescope Array (CTA). The CTA FRAMs are being deployed ahead of time to characterize the properties of the sites prior to the operation of the CTA telescopes; one FRAM has been running on the planned future CTA site in Chile for a year while two others are expected to become operational before the end of 2018. We report on the hardware and current status of operation and/or deployment of all the FRAM instruments in question as well as on some of the preliminary results of integral aerosol measurements by the FRAMs in Argentina and Chile.

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Madurowicz, Alexander, and Bruce Macintosh. "Integral Field Spectroscopy with the Solar Gravitational Lens." Astrophysical Journal 930, no. 1 (May 1, 2022): 19. http://dx.doi.org/10.3847/1538-4357/ac5e9d.

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Abstract The prospect of combining integral field spectroscopy with the solar gravitational lens (SGL) to spectrally and spatially resolve the surfaces and atmospheres of extrasolar planets is investigated. The properties of hyperbolic orbits visiting the focal region of the SGL are calculated analytically, demonstrating trade-offs between departure velocity and time of arrival, as well as gravity assist maneuvers and heliocentric angular velocity. Numerical integration of the solar barycentric motion demonstrates that navigational acceleration of dv ≲ 80 m s + 6.7 m s t year is needed to obtain and maintain alignment. Obtaining target ephemerides of sufficient precision is an open problem. The optical properties of an oblate gravitational lens are reviewed, including calculations of the magnification and the point-spread function that forms inside a telescope. Image formation for extended, incoherent sources is discussed when the projected image is smaller than, approximately equal to, and larger than the critical caustic. Sources of contamination that limit observational signal-to-noise ratio (S/N) are considered in detail, including the Sun, the solar corona, the host star, and potential background objects. A noise mitigation strategy of spectrally and spatially separating the light using integral field spectroscopy is emphasized. A pseudo-inverse-based image reconstruction scheme demonstrates that direct reconstruction of an Earth-like source from single measurements of the Einstein ring is possible when the critical caustic and observed S/N are sufficiently large. In this arrangement, a mission would not require multiple telescopes or navigational symmetry breaking, enabling continuous monitoring of the atmospheric composition and dynamics on other planets.

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Refsdal, Sjur, and Jean Surdej. "Gravitational Lensing." Highlights of Astronomy 9 (1992): 3–32. http://dx.doi.org/10.1017/s1539299600008716.

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AbstractAtmospheric lensing effects deform our view of distant objects; similarly, without any doubt, gravitational lensing perturbs our view of the distant Universe and affects our physical understanding of various classes of extragalactic objects. We summarize here part of the theoretical and observational evidences supporting these claims.After briefly reviewing the history of gravitational lenses, we recall the basic principles underlying the formation of gravitationally lensed images of distant cosmic sources. We describe a simple optical lens experiment, which was actually shown during the oral discourse, and which accounts for all types of presently known gravitational lens systems.The various optical and radio searches for new gravitational lens systems that are being carried out at major observatories are reviewed. State-of-the-art observations of selected gravitational lens systems, obtained with highly performing ground-based telescopes, are then presented. These include several examples of multiply imaged QSO images, radio rings and giant luminous arcs.Through the modeling of these enigmatic objects, we show how it is possible to weigh the mass of distant lensing galaxies as well as to probe the distribution of luminous and dark matter in the Universe. Among the astrophysical and cosmological interests of observing and studying gravitational lenses, we also discuss the possibility of deriving the value of the Hubble parameter Ho from the measurement of a time delay, and how to determine the size and structure of distant quasars via the observational study of micro-lensing effects.At the end of this paper, we conclude on how to possibly achieve major astro-physical and cosmological goals in the near future by dedicating, on a site with good atmospheric seeing conditions, a medium size (2-3 m) telescope to the photometric monitoring of the multiple images of known and suspected gravitational lens systems.

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Journal articles on the topic 'Telescopic lens'

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