ASTM F1753-96(2006)
(Specification)Standard Specification for Classification and Marking of Single-Lens Scopes for Use with Archery Bows
Standard Specification for Classification and Marking of Single-Lens Scopes for Use with Archery Bows
ABSTRACT
This specification covers the classification and marking of single-lens scopes used in conjunction with archery bows. The lenses are classified in terms of optical magnification, scope markings, and charts of the empirical relationship of the apparent magnification that the consumer can expect to obtain when a correctly marked lens is used under specific conditions. The visual acuity of the lenses is related to the magnification of the lens in general, and is dependent on other factors such as the specific individual, lens quality, and the size of the rear aperture used with the lens. This specification does not go beyond this definition of acuity.
SCOPE
1.1 This specification covers lenses and scopes used in conjunction with archery bows. It establishes a standardized system for the classification of these lenses in terms of their optical magnification, the marking of the scopes in which the lenses are mounted, and charts depicting the empirical relationship of the apparent magnification the consumer can expect to obtain when a correctly marked lens is used under specific conditions.
1.2 AcuityThe visual acuity of these lenses is related to the magnification of the lens in general. For the average subject there can be an improvement in acuity with lenses having apparent magnifications of 2 to 4 and a decrement in acuity with lenses of 6 and greater.
1.2.1 Acuity also is dependent on other factors, such as the specific individual, lens quality, and the size and quality of the rear aperture (peep) used in conjunction with the lens. Beyond this statement, acuity is not the subject of this specification.
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Standards Content (Sample)
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An American National Standard
Designation: F1753 – 96 (Reapproved 2006)
Standard Specification for
Classification and Marking of Single-Lens Scopes for Use
with Archery Bows
This standard is issued under the fixed designation F1753; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope apparent magnification, the metres-to-inches conversion factor
of 39.37 appears in the equation.
1.1 This specification covers lenses and scopes used in
2.1.4 focal length, n—distance, measured in metres, from
conjunction with archery bows. It establishes a standardized
the center of the subject lens to the point where incident plane
system for the classification of these lenses in terms of their
lightwavespassingthroughthelensarebroughttothesharpest
optical magnification, the marking of the scopes in which the
possible focus.
lenses are mounted, and charts depicting the empirical rela-
2.1.5 optical magnification, n—characteristic of a particular
tionship of the apparent magnification the consumer can expect
lens defined as the reciprocal of the lens focal length as
to obtain when a correctly marked lens is used under specific
measured in metres and stated in diopters.
conditions.
2.1.6 peep sight, n—rear sighting device placed in or onto
1.2 Acuity—The visual acuity of these lenses is related to
the bow string, having a small opening in it that the archer
themagnificationofthelensingeneral.Fortheaveragesubject
peersthroughtoviewthelensorscopebeingusedasasighting
there can be an improvement in acuity with lenses having
device.The combination of the lens and rear peep sight used in
apparent magnifications of 2 to 43 and a decrement in acuity
this manner mimics a primitive telescope.
with lenses of 63 and greater.
1.2.1 Acuity also is dependent on other factors, such as the
3. Classification
specific individual, lens quality, and the size and quality of the
3.1 Optical Magnification—This is the magnifying power
rear aperture (peep) used in conjunction with the lens. Beyond
of a lens as measured by the reciprocal of the focal length of
this statement, acuity is not the subject of this specification.
the lens in metres. It is expressed as a practical unit in terms of
2. Terminology a focal length equal to one metre (the unit diopter). The larger
the diopter number, the greater the magnifying power of the
2.1 Definitions:
lens.
2.1.1 apparent magnification, n—apparent increase in size
3.2 Apparent Magnification—This is the apparent increase
of an object as viewed through the subject lens held at a
in object size one experiences when viewing the object through
specific distance from the user’s eye.
one of these magnifying lenses. It is dependent on the
2.1.2 diopter, n—reciprocalofthefocallengthofthelensas
following two factors:
measured in metres. One diopter is the rating obtained when
3.2.1 The optical magnification of the scope lens as mea-
the constant 1 is divided by the focal length value of a lens
sured in diopters, and
having a 1-m focal length.
3.2.2 The distance the scope is placed from the user’s eye.
2.1.3 eye-to-scope distance (ETS), n—distance the (scope)
3.3 Apparent magnification is defined empirically by the
lens is placed from the individual’s eye when in use. If the
following relationship:
eye-to-scope distance is measured in metres, it is specified as
(ESM) and no conversion factor is required in the apparent Apparent magnification 5 1/ 1 2 D 3 ESM (1)
~ !
magnification formula. When the eye-to-scope distance is
where:
measured in inches, it is designated as (ESI). To calculate
D = lens optical magnification, diopters, and
ESM = eye-to-scope distance, m.
3.3.1 If the eye-to-scope distance is measured in inches
This specification is under the jurisdiction ofASTM Committee F08 on Sports
(ESI), the relationship becomes:
Equi
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