Product Description
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Category : Binoculars
Magnification : 7x
Objective : 35mm
Field of View : 487 ft @ 1000 yds
Eye : 17.3mm
Exit Pupil : 5mm
Short Focus : 16.4 ft
Prism Type : Porro
Weight :2 LB
Finish : Black Rubber Armor
Case : Carrying Case
From the Manufacturer
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The Monarch ATB 42mm with Dielectric High-Reflective Multilayer
Prism Coating binocular features brighter, sharper colors, crisp
and drastically improved low-light performance. A new body style
provides unparalleled strength and ruggedness in a package that
is comfortable to carry all day. With rugged rubber armor for
added durability and a firm grip even in the worst conditions,
Nikon guarantees every ATB to be 100% waterproof and fogproof,
each is backed by Nikon's 25 Year Limited Warranty and No-Fault
Repair/Replacement Policy. The new Monarch ATB 42mm with
Dielectric High-Reflective Multilayer Prism Coating binocular is
available in 8x42, 10x42 and 12x42. It is also available in Team
REALTREE models with the REALTREE APG HD camoue pattern.
Technical Specs
Additional Action EX Highlights:
* BaK 4 High Index Roof Prisms
* Tripod adaptable
* Long eye for eyeglass wearers
Warranty Information
Nikon is dedicated to quality, performance and total customer
satisfaction. If your Nikon binocular, Spotting or
Field requires service or repair not covered by our 25 Year
Limited Warranty, Nikon will repair or replace it (even it was
your fault) for just $10, plus return shipping and handling.
Excludes – StabilEyes, Laser Rangefinders and Spotting
/Field eyepieces.
FAQ's
Real field of view
Real field of view is the angle of the visible field, seen
without moving the binoculars, measured from the central point of
the objective lens. The larger the value is, the wider the
viewfield available. For example, binoculars with a wider field
of view are advantageous for locating fast-moving wild birds
within the viewfield. This also applies for finding small nebulas
or a cluster of stars in astronomical observations.
Apparent field of view
Apparent field of view is the angle of the magnified field when
you look through binoculars.
The larger the apparent field of view is, the wider the field of
view you can see even at high magnifications.
With the conventional method used previously, the apparent field
of view was calculated by multiplying the real field of view by
the binocular magnification. (With this formula, apparent field
of view wider than 65˚ is called wide field of view.)
After revision, Nikon's figures are now based on the ISO
14132-1:2002 standard, and obtained by the following formula:
tan ω' = τ x tan ω
Apparent field of view: 2ω'
Real field of view: 2ω
Magnification: τ
(With this formula, apparent field of view wider than 60° is
called wide field of view.)
For example, the apparent field of view of 8x binoculars with an
7.0°real field of view is as follows:
2ω' = 2 x tan(r x tan ω)
= 2 x tan(8 x tan 3.5)
= 52.1°
Relative Brightness
Relative brightness value is obtained by squaring the diameter
of the exit pupil. The greater the relative brightness is, the
brighter the image will be. With 8x42 binoculars, the brightness
is (42÷8)2= 28.1. This means that if the magnification is the
same, the larger the effective diameter of the objective lens,
the brighter the image will be.
Do binoculars with the same exit pupil offer the same
brightness?
No. Brightness may vary even if the exit pupil is the same. This
is because the a of light reaching the viewer's eyes varies
according to the number of lens elements and quality of
lens/prism coatings. Superior optical design and highquality
coating greatly contribute to the brightness of binoculars.
Brightness values specified in product brochures, etc. are
theoretical ones calculated in the design process. Please note
these factors when comparing actual brightness values.
Prisms
Prisms are what let you see a correctly oriented image when you
look through a pair of binoculars. There are two types of prisms
in common use, Porro prisms and roof prisms.
Roof prisms are essentially in line inside the optical tubes,
and make for a more compact set of binoculars. Roof prism
binoculars have straight tubes (the front/objective lens is in
line with the rear/ocular lens), and are therefore more compact,
an important consideration for the sportsman. They usually have
two pivot points between the tubes, and are more difficult to
adjust to the spacing of your eyes. Roof prisms can give an
optical image equal to the best Porro prisms, but for technical
reasons they usually do not. To be really good, roof prism
binoculars have to be in the high price class. Do not attempt to
economize on roof prism binoculars.
Porro prism binoculars can be identified by their offset tubes;
the objective lens is not in line with the ocular lens. The front
lenses are usually closer together than the rear lenses, but the
reverse can also be true, particularly in compact models. The
Porro prism design is usually optically superior to the roof
prism design, especially in medium priced class binoculars. Porro
prism binoculars have a single pivot between the two halves of
the binocular, and are therefore easy to adjust for the distance
between your eyes.
Like roof prisms, not all Porro prisms are created equal. BAK-4
prisms are the best; they are made of superior optical glass that
produces clearer images. These are what you want in your
binoculars. BK-7 prisms are also used, usually in lower priced
binoculars. These are satisfactory, but they are inferior to the
BAK-4 prisms. Some manufacturers will not tell you what kind of
prisms they use, usually because they are of inferior quality.
BAK-4 prisms show a truer round, which translates to better light
transmission and edge-to-edge sharpness
Prism Coatings
Multilayer coating is also applied to prisms to raise
transmittance. A roof prism system has one surface that does not
feature total internal reflection, so vapor deposition with
metals, etc. must be used to raise the reflectivity of this
surface. Also, phase-correction coating on roof surface ensures
high-contrast images.
*Binoculars' brightness and contrast are affected by not only
prism coatings, but also the number of objective lens and
eyepiece lens, and types of coatings.
Phase-correction coating
A roof (Dach) surface can cause phase shift of light that
affects image resolution. This phenomenon is caused by phase
differences arising from total light reflection on a roof (Dach)
surface and it can occur with even a perfectly processed prism.
Phase-correction coating is applied to the surface to minimize
loss of resolution, ensuring high-contrast images.
Twilight Factor
The factor that has the greatest impact on resolution or image
detail, will be dependent upon the a of light available
during the time of observation. During daylight hours, when your
eye pupil size will be only about 2 to 3mm, magnification will be
the principal factor in image resolution. At night, with the eye
pupil dilated to 6 to 8mm, aperture size is the controlling
factor. In twilight conditions both of these factors control
resolution effectiveness and the twilight factor is the term that
compares binocular performance under these conditions.
The twilight factor is calculated by taking the square root of
the product of the magnification and the aperture. The higher the
twilight factor, the better the resolution of the binocular when
observing under dim light conditions. For example, a 10 X 40
(twilight factor 20) would effectively resolve better under these
conditions than a 7 X 35 (twilight factor 15.4) even though the
10 X 40 has a smaller exit pupil. Remember, however, that the
twilight factor does not take into account the transmittance or
quality of the optical system.
- Package Dimensions: 7.95 L x 3.78 H x 7.32 W (inches).
- Package Weight : 2.51 pounds.
- Country of Origin : China.
- Rugged Waterproof, Fog proof Construction.