• This means that one could see it at the edge of a distortionless 40° AFOV (w/AFOV=2ε) eyepiece at f /4, regardless of its focal length (consequence of the field stop size, for any given FOV angle, being inversely proportional to eyepiece magnification). (telescope-optics.net)
  • The nature of the focal length and maximum aperture of the 14mm lens means that the elements are smaller and require less torque to drive them. (lenimar.com)
  • With its 6" aperture and long focal length of 1524mm, the 6" f/10 LX85 ACF telescope is the most compact and portable of the LX85 ACF offerings, yet still powerful enough to resolve stunning views of distant star clusters, planetary nebulae, and elusive galaxies - many of which appear tiny and featureless in the wide-angle telescopes so common today. (telescope.com)
  • Both telescopes have an aperture of 1.45m × 0.5m and a focal length of 35m. (esa.int)
  • This fine-quality German equatorial mount, which features fully automated GoTo slewing to thousands of objects via its innovative AudioStar controller, sets the standard for mid-sized telescope mounts. (telescope.com)
  • So, for example, if you have a telescope with an aperture of 200mm (8"), your Maximum Useful Magnification is 400x. (optcorp.com)
  • You can measure your pupil size with a gauge available from certain telescope suppliers. (astronomy.com)
  • Featuring an aluminum telescope optical tube and all-glass optics, including an antireflection-coated 60mm-aperture (2.36") achromatic glass objective lens, the Observer II 60mm yields crisp, bright images of the night sky. (telescope.com)
  • As a bonus, this special telescope kit also includes a full aperture film solar filter that fits over the front of your telescope. (binoculars.com)
  • It's your mis-aligned eye's pupil intersection with the aberrated exit pupil of your telescope/eyepiece combination. (birdforum.net)
  • Evidently, unlike the linear quality field, which only changes in proportion to F 3 , quality angular field changes in proportion to F 2 and in inverse proportion to the aperture diameter D . (telescope-optics.net)
  • The overall diameter should be large enough to allow an optical zone diameter larger than the pupil size in dim illumination. (reviewofoptometry.com)
  • The diameter of the exit pupil equals the aperture divided by the magnification. (astronomy.com)
  • So for 10×70 binoculars, the exit pupil diameter is 7mm. (astronomy.com)
  • Some people have dark-adapted pupils measuring nearly 9mm in diameter. (astronomy.com)
  • Or does exit pupil refer to the diameter of the ocular lenses? (birdforum.net)
  • Yes, all binoculars with the same magnification and objective diameter have the same exit pupil diameter. (birdforum.net)
  • Objective Lens Diameter: 24mm , Exit Pupil: 10.6mm - 3.8mm , Eye Relief: 4 in. (outdoorsmagazine.net)
  • The telescope's 3" aperture (or diameter) gathers a good amount of light from the night sky, for impressively bright and detailed views of celestial wonders. (telescope.com)
  • In optical terms, the anatomical pupil is the eye's aperture and the iris is the aperture stop. (wikipedia.org)
  • The image of the pupil as seen from outside the eye is the entrance pupil, which does not exactly correspond to the location and size of the physical pupil because it is magnified by the cornea. (wikipedia.org)
  • The problem is that if the exit pupil of a binocular is too large to fit into your eye, you lose some of the instrument's incoming light. (astronomy.com)
  • The exit pupil(s) of the binocular should be aligned with the pupils of your eyes in order for things to work right. (birdforum.net)
  • The technique of indirect binocular ophthalmoscopy starts with good dilatation of pupil with tropicamide and phenylephrine drops and examining fundus in the darkroom. (eophtha.com)
  • Your telescope's aperture is the main factor in what decides how much magnification you can use. (optcorp.com)
  • Because the size of the reticle changes with the magnification setting, a balance must be struck between it's being too small (thin, actually) at low magnifications and too coarse at the upper end. (sigforum.com)
  • This is limited by two factors: 1) your telescope's aperture, and 2) the conditions of the sky when you're observing. (optcorp.com)
  • some cats, reptiles, and foxes have vertical slit pupils, goats have horizontally oriented pupils, and some catfish have annular types. (wikipedia.org)
  • To switch to Narrow Field Mode the off axis distance of the LGS will be reduced to 10' off-axis and a dichroic mirror is inserted in the central aperture of the annular mirror. (eso.org)
  • The dilator pupillae, innervated by sympathetic nerves from the superior cervical ganglion, cause the pupil to dilate when they contract. (wikipedia.org)
  • Furthermore, the pupil will dilate if a person sees an object of interest. (wikipedia.org)
  • This is because the pupils in our eyes dilate in darkness. (astronomy.com)
  • Detail reproduction technology works to increase the fine detail rendering capabilities for a more three-dimensional, realistic image quality while diffraction-reducing technology helps to enhance the optical qualities of any lens by suppressing diffraction that is common when working at smaller apertures. (bhphotovideo.com)
  • When the wave encounters an obstruction, an aperture diffraction changes the direction of the wave. (medscape.com)
  • When the pupil size is smaller than 2.5 mm, the diffraction increases and sets a limit for visual acuity. (medscape.com)
  • The EF lens has a modestly wider aperture available, uses smaller filters (58mm vs. 67mm), and does not focus-extend. (lenimar.com)
  • Giant binoculars have front-lens apertures greater than or equal to about 4 inches (100mm). (astronomy.com)
  • Each of them consists of a Pupil re-imaging lens, a jitter actuator, and an additional pupil relay to create the pupil on the WFS lenslet array. (eso.org)
  • If that's correct, the size of the exit pupil is not related to blackouts but the size of the lens is. (birdforum.net)
  • A 2.1-megapixel Super CCD (producing 4.0-megapixel finished file sizes) and a 3x optical zoom lens offer good image quality, with a handful of exposure options that offer reasonable flexibility without getting too complicated. (imaging-resource.com)
  • For example, at the peak age of 15, the dark-adapted pupil can vary from 4 mm to 9 mm with different individuals. (wikipedia.org)
  • When the sphincter pupillae contract, the iris decreases or constricts the size of the pupil. (wikipedia.org)
  • After 25 years of age, the average pupil size decreases, though not at a steady rate. (wikipedia.org)
  • This is similar to a camera in which a large aperture lets in more light but decreases the depth of field. (cataractcoach.com)
  • This makes it possible to customize pupil dependent IOLs better to patient preferences. (medicalopedia.org)
  • For most monofocal IOLs in the average eye, the range of acceptably sharp vision without glasses is between ±0.25 D to ±0.5 D from the focal point, although it can be more in certain situations, such as with small pupils and in the presence of corneal aberrations. (cataractcoach.com)
  • The functional range then depends on the depth of field, which is related to pupil size, corneal aberrations, IOL characteristics and ambient lighting. (cataractcoach.com)
  • In addition, this method can collect the spectral information for each spatial location with coded aperture and dispersion element based on CS theory. (springeropen.com)
  • The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina. (wikipedia.org)
  • It appears black because light rays entering the pupil are either absorbed by the tissues inside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil. (wikipedia.org)
  • citation needed] The size of the pupil is controlled by the iris, and varies depending on many factors, the most significant being the amount of light in the environment. (wikipedia.org)
  • Light enters the eye through the pupil, and the iris regulates the amount of light by controlling the size of the pupil. (wikipedia.org)
  • The pupil gets wider in the dark and narrower in light. (wikipedia.org)
  • This condition is typified by chronically widened pupils due to the decreased ability of the optic nerves to respond to light. (wikipedia.org)
  • We used a small Australian freshwater fish (the western rainbowfish, Melanotaenia australis ) to determine whether populations showed variation in eye size and eye position, and whether this variation could be explained by environmental (light availability, turbidity) and ecological (predation risk, habitat complexity, invertebrate abundance) variables. (biologists.com)
  • The wide aperture also enables autofocusing in low light conditions. (lenimar.com)
  • The 24.2MP APS-C-sized Exmor APS HD CMOS sensor and BIONZ X image processor work together to produce high resolution, well-detailed imagery with minimal noise and notable low-light quality and sensitivity to ISO 25600. (bhphotovideo.com)
  • This aerial image is visualized 3 dimensionally when light is received by both pupils of the observer. (eophtha.com)
  • Lastly, visualization of the complete aerial image is achieved by adjusting inter-pupillary distance so that light from the observer and patient pupil is projected at similar points. (eophtha.com)
  • A larger aperture light spot is used for a fully dilated pupil and intermediate and smaller apertures for a smaller or undilated pupil. (eophtha.com)
  • The primary structure of the system contains fore optics, coded aperture, dispersion element and light field sensor. (springeropen.com)
  • Wavefront describes the curve corresponding to the position of multiple light rays exiting the eye that passed the different spots in the area of the pupil, emanating from the point source in the foveola after it passes through the optical system of the eye. (medscape.com)
  • The image formed on the retina from the light entering through the pupil is not a perfect point but a light disc (airy disc) surrounded by concentric dark and light rings. (medscape.com)
  • The slower mirror has about twice smaller relative aperture, thus its ray spot should be four times smaller (inversely proportional to the square of f -ratio for given linear field radius), but it is made larger for visual clarity . (telescope-optics.net)
  • A smaller-than-average OAD/OZD is recommended in cases of an interpalpebral fitting relationship as well as with a steeper-than-average corneal curvature. (reviewofoptometry.com)
  • The smaller the pupil size, the wider the depth of field. (cataractcoach.com)
  • However, in any human age group there is considerable variation in maximal pupil size. (wikipedia.org)
  • How important that variation in reticle size varies with the intended purpose of the sight. (sigforum.com)
  • No, small exit pupils work quite well in a good optical design that tolerates a bit of variation in alignment. (birdforum.net)
  • when compared to a 3-9x, or is everything kept in check by the typically overall-larger size of the optic? (sigforum.com)
  • APS-C format cameras using lenses projecting a full-frame-sized image circle avoid most vignetting problems. (lenimar.com)
  • Apart from the image sensor, the Leica Q2 Monochrom is otherwise virtually identical to the colour Q2 in terms of its features, performance, size and shape, and its build quality. (photographyblog.com)
  • A collimator forms pupil in which a motorized tip tilt mirror (Field Selector) allows to direct only part of the field to the Tip-Tilt Sensor. (eso.org)
  • It is a Shack Hartman sensor with 2 by 2 sub apertures working at a wavelength range of 980nm to 1800nm. (eso.org)
  • We discuss possible ways to enlarge the size of high-resolution area (isoplanatic patch) in fundus imagers equipped with adaptive optics. (spie.org)
  • Table-1) Larger field of view allows a quick glance at the fundus and hence more widely used in screening camps, pediatric eye examination and in eyes with a small pupil. (eophtha.com)
  • Also, women of the same age tend to have larger pupils than men, on average. (astronomy.com)
  • As compared to adults, the tumors in children tend to be more aggressive in terms of growth rate, tumor size, propensity to undergo malignant changes, and recurrence rate. (medscape.com)
  • The local slope of the wavefront curve at the particular spot within the pupil is derived from the actual image displacement of the point source from foveola as it passes through the optical system of the eye as compared to the ideal/predicted image of the ideal optical system. (medscape.com)
  • With patients exhibiting a larger-than-average palpebral aperture size where the upper lid is tangent to or above the limbus (see Figure 2), making a lid attachment fitting relationship very difficult to achieve, you"re best off using an interpalpebral fit. (reviewofoptometry.com)
  • A larger OAD/OZD, such as 9.8/8.4mm, is recommended for patients with larger-than-average pupil sizes and for athletes. (reviewofoptometry.com)
  • Buy a glass with a larger exit pupil. (birdforum.net)
  • Are the eyes of normal size and position? (vin.com)
  • Plots at left show the geometrical (distortion-free) FOV (GFOV) at which sagital coma ( S' ) would become clearly visible for 3 (above average) and 5 (average) arc minutes shape acuity. (telescope-optics.net)
  • In the dark it will be the same at first, but will approach the maximum distance for a wide pupil 3 to 8 mm. (wikipedia.org)
  • The Pupillometer measures pupil sizes in a range from 1mm to 9mm with an accuracy of 0.1mm. (medicalopedia.org)
  • In children, the male-to-female ratio is 2:1, with an average age at presentation of 10.1 years (range, 1-16 y). (medscape.com)
  • For astronomical use, a large exit pupil is desirable. (astronomy.com)
  • This allows both functions to take benefit from the two viewing directions and from the large ASTRO aperture, and to operate in densely populated sky areas. (esa.int)
  • From this photo it is obvious that the aperture size of a camera makes a large difference in the depth of field. (cataractcoach.com)
  • You get the point: none of this is one-size-fits-all, and no single procedure will suit every patient. (optometrytimes.com)
  • You can also take the aperture in inches and multiply it by 50 to get the same result. (optcorp.com)
  • I really consider the professional sized DSLRs the SUV/pickup trucks of the camera world. (typepad.com)
  • However, including people, cars, and other human sized things helps to pull your viewer into the scene. (starcircleacademy.com)
  • Its angular size needs to be ~5 arc minutes for its shape to be recognized by an average eye. (telescope-optics.net)
  • The reverse is true, so control of pupil size is controlled by differences in contraction intensity of each muscle. (wikipedia.org)
  • The 4 LGSs are 64' off axis to probe atmospheric turbulence and the averaged WFS signals will be used to correct for the turbulent ground layer. (eso.org)
  • Gaia contains two identical telescopes, pointing in two directions separated by a 106.5° basic angle and merged into a common path at the exit pupil. (esa.int)
  • Unfortunately, there's no hard and fast rule that correlates pupil size with age. (astronomy.com)
  • Because it may be hard for a clinician's eye to estimate pupil size by a single picture, the Pupillometer records 3 seconds to overcome small continuous oscillations and presents an average size. (medicalopedia.org)