`
`APPLE V COREPHOTONICS
`IPR2020-00905
`Exhibit 2016
`Page 1
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`APPLE V COREPHOTONICS
`IPR2020-00905
`Exhibit 2016
`Page 1
`
`

`

`1
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`
`
`
`Library of Congress Cataloging-in-Publication Data
`
`Kingslake, Rudolf.
`Optics in photography / Rudolf Kingslake.
`.
`cm.
`“A Publication of SPIE—the International Society for Optical
`Engineering.”
`Includes bibliographical references and index.
`ISBN 0-8194-0763-1
`1. Photographic optics.
`TR220.K56
`1992
`771.3'5--de20
`
`I. Title.
`
`92-11861
`CIP
`
`Published by SPIE—TheInternational Society for Optical Engineering
`P.O. Box 10
`Bellingham, Washington 98227-0010
`Design: Matt Treat
`Composition: Carrie Binschus
`
`Copyright © 1992 The Society of Photo-Optical Instrumentation Engineers
`
`All rights reserved. Nopartof this publication may be reproduced ordistributed
`in any formor by any means without written permission of the publisher.
`
`109876543
`Printed in the United States of America
`
`APPLE V COREPHOTONICS
`IPR2020-00905
`Exhibit 2016
`Page 2
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`APPLE V COREPHOTONICS
`IPR2020-00905
`Exhibit 2016
`Page 2
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`

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`LS ULLAL LLC Lidia plitle LLLUSL DE VICEWEU MOLL APPLOALLUALELY LLs COLLELL CELILEL
`ofperspective, so that the angles subtendedat the eye by the various images
`in the picture will be the same as the subtense anglesof the original objects
`at the camera lens. For contact prints, the center of perspective corre-
`spondsto the actuallocation of the lens in the camera,opposite the middle
`of the picture anddistantfromit by the focal length of the cameralens.For
`enlargements, the distance of the center of perspective from theprint is
`found by multiplying the focal length of the camera lens by the enlarge-
`mentratio. Thus, for a negative made ina 35mmcamera witha 50 mm(2-
`inch) lens, and enlarged 10 times in printing, the center of perspective is
`at 20 inches from the print, and the picture should be viewed from this
`point. Thegainin realism obtained byenlarging small negatives in this way
`is quite marked and often astonishing.
`Thelateral position of the eye in relation to the center of perspective
`isalso important. This fact explains the seriousdistortion that results when
`we look at a motion-picture screen from the end ofthe front rowofseats,
`the center of perspective being actually located on a line joining the
`projector to the screen. In planning a large mural, whichis to be viewed
`from the floor of a room, it is advisable to have the camera lowand use the
`rising front. The opposite effect, with the camera looking down on the
`subject, would be very unpleasantin suchacase.
`
`The Field Covered by a Lens
`Every lens projects light onto a circularfield thatis limitedin size by the
`vignetting or cutting of oblique light by the lens barrel. However, in very
`few lenses is the definition sharp to the extremelimit of this circle of
`illumination. Since good definition is required in any practical application
`of the lens, it is customary tostate the field of a lens in terms ofthe angle
`over which good definition is obtainable (Fig. 1.8). This angle generally
`increases somewhatasthe lens is stopped downto a smaller aperture.
`Since most photographs are taken on a square or rectangularfilm area,
`it is necessary that the film format should fit into the circle of good
`definition of the lens. Thus, the diameter of this circle must be equalto, or
`greater than, the diagonal of thefilm.
`
`The “Normal” Focal Length for a Camera Lens
`For ordinary photography, the “normal”field is usually such that the
`diagonal of the negativeis equal to the focal length ofthe taking lens. This
`
`APPLE V COREPHOTONICS
`IPR2020-00905
`Exhibit 2016
`Page 3
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`APPLE V COREPHOTONICS
`IPR2020-00905
`Exhibit 2016
`Page 3
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`

`

`
`
`8
`
`OPTICS IN PHOTOGRAPHY
`
`
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`Figure 1.8. Thecircle ofillumination and the circle of definition of a lens.
`
`computestobe a total field of 53°, or a half-field of 26.5°. As has been
`mentioned,this angle is rather wider than the eye can cover at a glance,
`but in practice we tend to view most photographsfroma pointwell beyond
`the centerofperspective, and we unconsciously scan a print with oureyes.
`Suchanangleof view is therefore not objectionable. Many photographic
`prints, too, are cropped in printing so that the wholeofthelensfield is not
`recorded.
`A wide-field lens will cover an angular semifield of about 30° to 35°,
`and a true wide-angle lens will cover a semifield of 45° to 50° (see Fig. 1.9).
`Hence, a givenfilm format will be covered adequately by a wide-angle lens
`havinga focal length equal to about half the picture diagonal. Naturally,
`the field covered by the camera will not be increased byusing a wide-angle
`lens of the same focal length as the normallens; we cangain field only by
`the use of a shorter-than-normalfocal length.
`Somenarrow-angle lenses are loosely called “telephoto”lenses because
`they have a longer focal length than the normal lens and thus give a
`picture to a larger scale. However,
`the name “telephoto” should be
`restricted to a lens of a particularly compacttype of construction (see page
`148), in which the distance from the front ofthelens to thefilm plane is
`
`i
`
`:
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`APPLE V Corrs
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`a
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`Exhibit 2016
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`APPLE V COREPHOTONICS
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`45° WIDE ANGLE
`
`35° WIDE FIELD
`
`24° NORMAL STILL CAMERA
`
`14° MOTION PICTURE
`
`Fes
`
`(LENS AXIS)
`
`Figure 1.9. Some typical angular fields of lenses.
`
`less than the focal length ofthelens.
`In motion-picture photographyit has always been customary to use
`relatively long-focus lenses, the “normal” angular semifield being anly
`about 14°. This was probably doneoriginally to keep the camera well away
`from the actors in orderto give them greater freedom of movement along
`theline ofsight. If the camera wereclose to the subject, with a short-focus
`lens, the apparent size of the actors would appear to grow orshrink rapidly
`as they moved, and they might even walk completely out of focus in a couple
`of steps! Moreover, the “panningdistortion” mentioned on page20 is less
`noticeable if a long-focus lens is used. The use of a narrowangularfield
`greatly helps the lens designer to make wide-aperture lenses of good
`quality, which are very necessary with motion-picture cameras having a
`fixed exposure time.
`The matter of perspective must not be overlooked in this connection,
`as it is generally desirable that the center ofperspective shouldfall at about
`the middle of the audience in a theatre. Hence the angular field of the
`camera should be about twicethat of the projector, which again brings the
`camera semifield to about 14°. A wide-angle movie lens then covers a half-
`angle of about 20°, whichis actuallyless than thefield of a normallensin
`still photography.
`Thefollowing table of picture diagonals for some standard film sizes
`maybeofinterest. They are taken from ANSI Standard PH3.501-1987.
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`APPLE V COREPHOTONICS
`IPR2020-00905
`Exhibit 2016
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`APPLE V COREPHOTONICS
`IPR2020-00905
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`
`10
`PTICS IN PHOTOGRAPHY
`
`(a) Still cameras
`
`Diagonal
`
`Film name
`Negative area
`(mm)
`(inch)
`Disc and Minox
`8x1llmm
`13.6
`0.53
`110
`13x 17mm
`21.4
`0.84
`half 135
`17% x 24mm
`30.1
`1.19
`126
`28 x 28% mm
`40.0
`1.57
`135
`24 x 36mm
`44.0
`1.73
`828
`28 x 40 mm
`48.8
`1.92
`Sq. 127 (1% x 1% in.)
`41x 41mm
`58.0
`2.28
`127 (14% x 2% in.)
`41 x 56 mm
`69.4
`213
`Sq. 120 (24% x 2% in.)
`56 x 56 mm
`79.2
`3.12
`120 (244 x 3%in.)
`56 x 82/4 mm
`99.7
`3.93
`116
`244 x 44 in.
`125.2
`4.93
`Y-plate
`34% x 44 in.
`135.9
`5.35
`4x5in.
`162.6
`6.40
`5x 7in.
`218.5
`8.60
`
`(b) Motion-picture cameras
`
`Normalfocal
`Camera
`Projector
`length of
`
`Size
`Frame
`Diagonal
`Gate
`Diagonal
`cameralens
`(mm)
`(mm)
`(mm)
`(mm)
`19.05%25.37
`31.75.
`17.26 23.01 28.76
`16.03 22.05
`27.26
`15.24 20.96 25.91
`7.42*10.22
`12.63
`7.21965
`12.05
`4.22 x 5.77
`tld
`4.01536
`6.69
`3.51 x 4.80
`5.95
`3.28 x 4.37
`5.46
`
`35mmsilent
`35mm sound
`16mm
`Super-8
`8mm
`
`2 inch (50 mm)
`2 inch (50 mm)
`1 inch (25 mm)
`%inch (13 mm)
`= inch (13 mm)
`
`“True” and “Apparent” Perspective
`From the preceding discussion it should be clear that if we look at a
`photograph from some point other than its true center of perspective, we
`must expect to see a distorted representation of the original scene. For
`instance,
`if our eyes are considerably too far away from the picture,
`foregroundobjects will appear too large, and backgroundobjects relatively
`too small. Thiseffectis particularly noticeable in photographs taken with
`a wide-angle lens, suchas that in Fig. 1.10. The centerofperspective of the
`lower photographis at about 6 inches from theprint, andifoureyeis placed
`there, we have the impression that we are looking at a car from a reasonable
`distance away. For the upper picture, a wide-angle lens was used and the
`camera was movedvery close to the car. The center of perspective of the
`
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`APPLE.V.COREPHOTONIG
`
`Exhibit 2016
`Page 6
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`APPLE V COREPHOTONICS
`IPR2020-00905
`Exhibit 2016
`Page 6
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