##### focal length

- The f-number ("relative aperture"), N , is defined by N = f/E N , where f is the focal length and E N is the diameter of the entrance pupil. (wikipedia.org)
- Increasing the focal length of a lens (i.e., zooming in) will usually cause the f-number to increase, and the entrance pupil location to move further back along the optical axis. (wikipedia.org)
- The f-number of an optical system such as a camera lens is the ratio of the system's focal length to the diameter of the entrance pupil. (wikipedia.org)
- The f-number N or f# is given by: N = f D {\displaystyle N={\frac {f}{D}}\ } where f {\displaystyle f} is the focal length, and D {\displaystyle D} is the diameter of the entrance pupil (effective aperture). (wikipedia.org)
- A 100 mm focal length f/4 lens has an entrance pupil diameter of 25 mm. (wikipedia.org)

##### nodal point

- Panoramic photographers often incorrectly refer to the entrance pupil as a nodal point , which is a different concept. (wikipedia.org)
- Wouldn't it be great if everyone entered their values for their NPP / Nodal Point / Entrance Pupil for lens and camera combinations. (panotools.org)
- Wouldn't it be great if everyone entered their values for their Nodal Point / Entrance Pupil for lens and camera combinations. (panotools.org)

##### lens

- The entrance pupil is the image of the physical aperture, as seen through the front of the lens. (wikipedia.org)
- The pupil itself, which lens designers would call the aperture , is in a slightly different location because the image is magnified by the cornea . (wikipedia.org)
- In an optical system, the entrance pupil is the optical image of the physical aperture stop , as 'seen' through the front of the lens system. (wikipedia.org)
- The corresponding image of the aperture as seen through the back of the lens system is called the exit pupil . (wikipedia.org)
- If there is no lens in front of the aperture (as in a pinhole camera ), the entrance pupil's location and size are identical to those of the aperture. (wikipedia.org)
- The second table shows the actual entrance pupil distance which is only dependent on the lens itself. (panotools.org)
- Facing the side of the lens, the distance from the base of the lens to the Entrance Pupil. (panotools.org)
- A negative value means the entrance pupil is before the lens base. (panotools.org)
- A negative value means the entrance pupil is before the lens base, such is the case with many telephoto lenses. (panotools.org)
- This is easy to measure and is dependent only on the camera body The second table shows the actual entrance pupil distance which is only dependent on the lens itself. (panotools.org)
- To calculate the Entrance pupil distance add the Tripod Mount Length (L1) from the camera and the Entrance Pupil Length (L2) from the lens. (panotools.org)
- I just did some measurements and found an Entrance Pupil Length of 47mm for this lens. (panotools.org)
- An entrance pupil at infinity makes the lens object-space telecentric. (wikipedia.org)
- If both pupils are at infinity, the lens is double telecentric (or bi-telecentric). (wikipedia.org)
- Light energy enters the eye through the cornea, through the pupil and then through the lens. (wikipedia.org)
- Treat the lens as if it were a pinhole at distance S 2 {\displaystyle S_{2}} from the image plane (technically, the center of perspective of a rectilinear lens is at the center of its entrance pupil): Now α / 2 {\displaystyle \alpha /2} is the angle between the optical axis of the lens and the ray joining its optical center to the edge of the film. (wikipedia.org)
- The entrance pupil diameter is not necessarily equal to the aperture stop diameter, because of the magnifying effect of lens elements in front of the aperture. (wikipedia.org)

##### diameter

- The entrance pupil of the human eye , which is not quite the same as the physical pupil , is typically about 4 mm in diameter. (wikipedia.org)
- Refraction in the cornea causes the effective aperture (the entrance pupil in optics parlance) to differ slightly from the physical pupil diameter. (wikipedia.org)
- The entrance pupil is typically about 4 mm in diameter, although it can range from 2 mm (f/8.3) in a brightly lit place to 8 mm (f/2.1) in the dark. (wikipedia.org)
- The pupil magnification of an optical system is the ratio of the diameter of the exit pupil to the diameter of the entrance pupil. (wikipedia.org)

##### magnification

- Exit pupil Transmittance Pupil magnification Greivenkamp, John E. (2004). (wikipedia.org)
- Specifically, coma is defined as a variation in magnification over the entrance pupil. (wikipedia.org)
- The pupil magnification is used in calculations of the effective f-number, which affects a number of important elements related to optics, such as exposure, diffraction, and depth of field. (wikipedia.org)
- For all symmetric lenses, and for many conventional photographic lenses, the pupils appear the same size and so the pupil magnification is approximately 1. (wikipedia.org)

##### telescope

- In a refracting astronomical telescope the entrance pupil is identical with the objective. (wikipedia.org)

##### lenses

- Most lenses have an adjustable diaphragm, which changes the size of the aperture stop and thus the entrance pupil size. (wikipedia.org)

##### aperture stop

- The aperture stop is the aperture setting that limits the brightness of the image by restricting the input pupil size, while a field stop is a stop intended to cut out light that would be outside the desired field of view and might cause flare or other problems if not stopped. (wikipedia.org)

##### size

- In photography, the size of the entrance pupil (rather than the size of the physical aperture itself) is used to calibrate the opening and closing of the diaphragm aperture . (wikipedia.org)
- Similar to the eyes of other mammals, the human eye's non-image-forming photosensitive ganglion cells in the retina receive light signals which affect adjustment of the size of the pupil, regulation and suppression of the hormone melatonin and entrainment of the body clock. (wikipedia.org)
- The size of the pupil, which controls the amount of light entering the eye, is adjusted by the iris' dilator and sphincter muscles. (wikipedia.org)
- As soon as the eye moves rapidly to acquire a target (saccades), it re-adjusts its exposure by adjusting the iris, which adjusts the size of the pupil. (wikipedia.org)
- Another consequence of this design is that the entrance pupil varies in size during the tracking of a target. (wikipedia.org)

##### angle

- The geometric location of the entrance pupil is the vertex of the camera's angle of view and consequently its center of perspective , perspective point , view point , projection centre or no-parallax point . (wikipedia.org)
- When viewed at large angles from the side, the iris and pupil may still be visible by the viewer, indicating the person has peripheral vision possible at that angle. (wikipedia.org)
- In this case, the solid angle of interest is the solid angle subtended by the optical system's entrance pupil. (wikipedia.org)
- This has the effect of changing the entrance pupil shape as a function of angle (resulting in the path of light being partially blocked). (wikipedia.org)

##### Database

- The Entrance pupil database needs constant enhancement. (panotools.org)

##### center

- The outside world appears to be seen from the point at the center of the entrance pupil. (wikipedia.org)
- The iris is the pigmented circular structure concentrically surrounding the center of the eye, the pupil, which appears to be black. (wikipedia.org)

##### distance

- They must be designed for optimal performance for a specific distance to this entrance pupil (i.e. with minimum aberrations for this distance). (wikipedia.org)

##### image

- The entrance pupil is usually a virtual image: it lies behind the first optical surface of the system. (wikipedia.org)

##### human eye

- The apparent location of the anatomical pupil of a human eye (black circle) is the eye's entrance pupil. (wikipedia.org)
- In the human eye, the pupil is the aperture. (wikipedia.org)

##### optical systems

- Eyepieces are optical systems where the entrance pupil is invariably located outside of the system. (wikipedia.org)

##### back

- whereas with a microscope eyepiece the entrance pupil is close to the back focal plane of the objective, mere inches from the eyepiece. (wikipedia.org)

##### field

- The 200 mm lens's entrance pupil has four times the area of the 100 mm lens's entrance pupil, and thus collects four times as much light from each object in the lens's field of view. (wikipedia.org)

##### thirds of pupils

- At age 11, approximately two thirds of pupils join the senior school from its two junior schools, King's Hawford and King's St Albans, while others come from maintained schools in the city of Worcester and the surrounding areas that include Malvern, Redditch, Kidderminster, Evesham and Pershore. (wikipedia.org)
- The college also departed from the full boarding tradition of the English public school and allows day pupils, although over two thirds of pupils board. (wikipedia.org)

##### Focal Length

- The primary function of the panoramic head is to precisely set the point of rotation about the entrance pupil for a given lens and focal length, eliminating parallax error. (wikipedia.org)

##### main entrance

- The gates on the main road date from 1824 and were designed by Henry Hakewill In 1842 further major rebuilding of the south east front was completed, and later Sir Charles Isham commissioned the building of a new façade with porch to the north-west front, which is now the distinctive main entrance to the Hall. (wikipedia.org)
- A' block houses the main entrance/reception, office, main hall, canteen, gymnasium and the English and modern foreign language departments. (wikipedia.org)
- Its main entrance is on Harrow Road (west of where Ladbroke Grove and Chamberlayne Road meet). (wikipedia.org)

##### literacy

- Alwasilah (2006) proposes that the four levels of literacy are taught in stages in accordance with the levels of education: the first level of literacy is taught to elementary-school pupils, the second level to junior-high-school students, the third level to senior-high-school students, and the fourth level to university students. (blogspot.com)
- It also houses the main literacy block for those pupils with problems with literacy. (wikipedia.org)

##### examination

- Her parents encouraged her to pursue a higher course of instruction, and consequently, after a successful entrance examination, she became a student of the Girls' High and Normal School, as it was then called. (wikipedia.org)
- An entrance examination is held in January for 9+, 10+ and 11+ and in November for 13+ for admission in the following September. (wikipedia.org)

##### school

- Phlebotomy School Bleeds Butte County Pupils For $ Phlebotomy training is the training that is given folks wanting to become phlebotomists. (freecnatrainingprograms.com)
- These are: King's Hawford: (ages 2-11, c.320 pupils), formerly an autonomous fee-paying prep school named Hawford Lodge, purchased by King's in 1992, situated north of central Worcester. (wikipedia.org)
- King's St Alban's: (ages 4-11, c.215 pupils), formerly the Cathedral Choir School, amalgamated with King's in 1943, situated adjacent to the senior school. (wikipedia.org)
- King's Worcester: (ages 11-18, c.930 pupils), the senior school. (wikipedia.org)
- citation needed] From 1945 to 1976, the school participated in the direct grant scheme, accepting pupils funded by central government on a competitive basis. (wikipedia.org)
- There are currently about 660 pupils enrolled at the school, aged between 13 and 19. (wikipedia.org)
- Additionally, there are about 310 pupils aged from 3 to 13 at The Downs, Malvern College prep school, in nearby Colwall in Herefordshire. (wikipedia.org)
- The novelist C. S. Lewis, author of The Chronicles of Narnia, is a former pupil of the school. (wikipedia.org)
- Having traditionally been a school for boys aged from 13 to 18 years old, in 1992 it merged with Ellerslie Girls' School and Hillstone prep school to become a coeducational school for pupils aged 3 to 18 years old. (wikipedia.org)
- At the age of 14, she graduated from the Wells Grammar School, Blossom Street, Boston, one of ten honor pupils who received silver medals. (wikipedia.org)
- The school caters to pupils from the ages of 4 through to 18 or 19 and is open to children of all religious denominations. (wikipedia.org)
- The parking area for the school vans and buses is available near the entrance gate. (wikipedia.org)
- An extensive network of school buses, which St Helen & St Katharine shares with Abingdon School, bring pupils to the school from across Oxfordshire, Berkshire and surrounding counties. (wikipedia.org)
- citation needed] Close links with Abingdon School add a co-educational dimension, with some joint sixth form teaching and collaboration in other activities, including a joint Critical Thinking course taken by all Lower Sixth pupils. (wikipedia.org)
- A major centre of musical culture of the time, Bologna had a flourishing school of violinists associated with Ercole Gaibara and his pupils, Giovanni Benvenuti and Leonardo Brugnoli. (wikipedia.org)
- Gowerton School today serves pupils from the north and west of the Gower peninsula and from the Swansea suburbs of Gowerton, Waunarlwydd and Dunvant from age 11 to 18, with a successful sixth form specialising in A level and Welsh Baccalaureate courses. (wikipedia.org)
- It is mandatory for pupils in Austria to complete nine years of school, four years in elementary school (Volksschule) and four years in a school for lower secondary education (Hauptschule) or grammar school (Gymnasium). (wikipedia.org)
- Pupils who want to get a degree have to complete four to five years at an institution of higher education (Höhere Schule) or a vocational school with higher education entrance qualification (Berufsbildende Höhere Schule). (wikipedia.org)
- Most of these schools require an entrance exam or demand high marks on your last school certificate. (wikipedia.org)
- The evacuees included a boys' preparatory school, whose pupils included the young William Franklyn, and girls in the care of the Barnardo's charity. (wikipedia.org)

##### lens

- Wouldn't it be great if everyone entered their values for their NPP / Nodal Point / Entrance Pupil for lens and camera combinations. (panotools.org)
- The second table shows the actual entrance pupil distance which is only dependent on the lens itself. (panotools.org)
- Facing the side of the lens, the distance from the base of the lens to the Entrance Pupil. (panotools.org)
- A panoramic tripod head is a piece of photographic equipment, mounted to a tripod, which allows photographers to shoot a sequence of images around the entrance pupil of a lens that can be used to produce a panorama. (wikipedia.org)

##### former

- Seven former pupils were among 'the few' who took part in the Battle of Britain. (wikipedia.org)

##### schools

- Across the two schools, in total, there are nearly 1000 pupils. (wikipedia.org)
- Enrollment to these schools are subjected to pupils with excellent public examinations result (5A for UPSR and 7A for PMR) as well as in co-curricular activities. (wikipedia.org)

##### numbers

- Further expansion of pupil numbers and buildings continued between the end of the First World War in 1918 and the start of the Second World War in 1939. (wikipedia.org)
- Sports teams are consistently successful in local, regional and national competitions and significant numbers of pupils play representative sport at county, regional and national level. (wikipedia.org)

##### excellent

- The 2011 inspection report under the new Welsh inspection framework noted the school's outstanding ethos, inspiring leadership, good performance and excellent prospects, with high academic expectations and achievements, excellent care for pupil welfare and sector leading use of ICT in teaching. (wikipedia.org)

##### Center

- According to the Kakheti office of the Human Rights Center the teacher hit a 5th-grade pupil against the wall and desk. (humanrights.ge)

##### final

- pupils dilate, widened by the wonder of this final passage, noting the last movement, as fingers curl, and clench, and still. (hubpages.com)

##### west

- Its other entrance, Alma Place (the West Gate, almost opposite Greyhound Road) is also on the north side. (wikipedia.org)

##### follows

- It offers mixed-sex mainstream education that follows the UK National Curriculum to around 1,465 pupils aged 2 to 18. (wikipedia.org)

##### Road

- It is located five miles (8 km) south of Helston, on the main A3083 Helston to Lizard Road, turn left at Cury Cross Lanes (Wheel Inn) and the entrance is 300 yd (270 m) on the right. (wikipedia.org)