The first thing to do, as soon as a pair of binoculars is used, is to adjust the distance between the two eyepieces of the instrument according to your pupils in order to see only one well-circular image Resume the Fujinon doc schema.
As we saw under the "Astigmatism" heading, sometimes you will see a slight blurring around the edges with conventional binoculars. We advise those who want absolutely clear vision to choose Fujinon aplanatic binoculars (F).
The lenses are polished with extreme precision, and thanks to special surface machining techniques, and great patience, defects related to astigmatism are significantly reduced.
The Top of the Line binoculars: FMTRC-SX with aplanatic technology.
The Fujinon aplanatic technique (F) eliminates image blurring. With Fujinon 7 x 50 FMTR binoculars, the subject of view appears as clear at the edges of the field of vision as at the centre. Even the smallest image distortions, recognizable in vertical and horizontal lines that seem slightly curved through high-end binoculars, are reduced by half with the aplanatic technology. Their wide 23 mm pupillary distance provides maximum comfort for usage and ensures that those who wear glasses will have a complete field of vision.
Every optical system - whether it is the simplest magnifying glass or the most well designed photographic lens - suffers to a greater or lesser degree from astigmatism and distortion. Astigmatism means that the subjects in the centre of the field of vision are clear while in the areas at the edges of the field of vision the clarity seems to break down and become distorted. The opposite is also true. To identify these phenomena, specialists speak about tangential astigmatism and sagittal astigmatism. With Fujinon aplanatic binoculars (F), tangential astigmatism is barely measurable, and sagittal astigmatism has been reduced by 40% over other very high quality binoculars.
There is nothing clearer!
The interior surface of the binoculars equipped with this technology helps easily identify them. Yellow circles on the eyepieces and scale identify these binoculars as having the advantages of the Fujinon aplanatic technology.
A 'plus' that will especially interest those who wear glasses: the large distance between the eye and the exit aperture (23 mm) will provide them with more comfortable usage.
Field of vision:
Field of vision means the section of the subject visible through the binoculars. The size of the field of vision depends upon the magnification and distance of the subject, as well as the wide-angle aspect of the binoculars... The greater the magnification, the narrower the field of vision. The field of vision is expressed in metres (with the subject at 1000 m) or in degrees. For seven times magnification, the angle is 7.1°, and at one thousand metres, one can see 124 metres. However, there are binoculars with larger fields of vision (in this case >50°); they have a "wider angle" and thus, one can see more comfortably and more naturally. For example, Fujinon binoculars in the 7 x 50 MT series open to 7.30°, and one can see 131 metres at one thousand metres. Therefore, you have a better field of vision.
This datum is very important for marine applications, and it is one of the great advantages of Fujinon binoculars.
C: indicates that these binoculars are also equipped with a Compass.
CF: for Centre Focus. New central focusing system from one metre to infinity.
D/N: Day/Night vision.
ED: for Extra Low Dispersion. High-end optics reducing potential chromatic aberrations to a minimum.
F: If the binocular name contains an F, this means that the model is aplanatic.
HB: for binoculars with strong magnification and high brightness Hunting Binoculars.
HS: For hunting and hiking Hunting Series.
LF & MF: new series of Fujinon binoculars with the roof prism.
MT: An abbreviation for Marine Tested waterproof.
R: Rubber coated binoculars. This anti-shock coating is very practical for wet hands.
SX : The two letters SX indicate that the lenses and prisms have been treated using the special, exclusive EBC (Electron Beam Coating) process patented by FUJINON. This process ensures an overall light transmission index of 95% across the entire visible spectrum. To truly appreciate this value, it is important to know that other binoculars only rarely approach it. Additionally, this process greatly improves salt resistance.
FUJINON prisms are cut from optical glass with a high refraction index, Bak 4, which helps optimize contrast and definition of the image.
TS : for Techno Stabi, Fujinon stabiscope binocular models with gyroscopic movement compensation motors.
WP : for Water Proof. In fact, these binoculars float.
The second figure describes the diameter of the front lenses. On 7 x 50 binoculars, it is 50 mm. The larger the diameter, the more light can enter, providing clearer, brighter vision.
Minimum focusing distance:
This defines the minimum distance at which you can focus. It is important to know this distance when observing subjects that are close up. For hiking binoculars, this distance is typically five metres and approximately ten to twenty metres for marine binoculars used to observe far away objects.
You have almost certainly seen photographs taken with a wide-angle lens that gives a visible and desired distortion. With good binoculars, this distortion should not be visible, and yet it exists. It can be seen by observing a building where the vertical and horizontal lines are no longer entirely straight, but slightly curved.
Fujinon lens and case production quality helps considerably reduce these defects often observed in entry-level products. Additionally, Fujinon aplanatic technology (F) helps further reduce small distortions by half, making them almost non-existent. All Fujinon binoculars with this code (F) are remarkable high-end products that display almost perfect images.
Waterproofing - Unsinkability:
What does waterproof mean?
Rubber Coating does not make binoculars waterproof in the strict sense of the term. It only protects them against shocks and makes them easier to use with wet hands. If one wants truly waterproof binoculars, beware of descriptions such as 'spray proof', 'fog resistant', 'water resistant', or 'all weather'. These binoculars are not truly waterproof. Waterproof binoculars must be able to handle immersion to a certain depth for a certain amount of time without damage. Fujinon binoculars are all truly waterproof and completely fulfil the conditions for US Navy MT (Marine Tested) tests: immersion for at least five minutes at a depth of 4.5 metres.
Do not be fooled by descriptions such as 'military style' or 'military design'. Select MT Marine Tested binoculars because they alone are manufactured according to the specifications of the US army, whose tests are the most rigorous in the world. This means that the cases are adjusted with great precision, and are never made of plastic, but always of very high quality lightweight aluminium alloys. After the binoculars are sealed, to reduce the possibility of forming moulds that can often cause a cloudy film, the binoculars are filled with nitrogen. All Fujinon MT binoculars have successfully passed the four tests required by the American army: overall quality, optical quality, usage characteristics, and environments.
Some Fujinon binoculars are described as 'floating'. This means that they are completely unsinkable (7 x 50 WM and 7 x 50 WPC). No other binoculars of this quality float, without their strap.
The first figure in the product description indicates the magnification of the binoculars. With 7x50 magnification, you will see the subject 7 times larger than with the naked eye.
This is calculated by squaring the diameter of the exit aperture
With a 7 x 50 FMTR, that gives 7 x 1 x 7.1 = 50.4.
With a 10 x 60 HB, that gives 6 x 6 = 36.
These data are calculated for informational purposes such as the crepuscular index for the ability of a pair of binoculars to help identify details under poor light conditions. But, for the same dimensions, all binoculars give identical indices. The quality of the lenses, coatings, and parallelism adjustments are not taken into account. Therefore, it is highly relative and insufficient by itself.
A rubber protective coating protects the binoculars and makes them easier to hold and more secure, regardless of the meteorological conditions. This protective coating reduces shock density and gives your binoculars a longer life.
It is not this rubber coating that makes the binoculars waterproof, but rather the overall construction of the case under pressurized, inert gas. As all Fujinon binoculars are waterproof, after usage at sea, be sure to rinse them with fresh water to prevent salt corrosion.
The 7 x 50 WPC binoculars have a special high durability polycarbonate case that allows this model to float on its own.
The diameter of the exit aperture can be obtained by dividing the lens diameter by the magnification. Therefore, 7 x 50 binoculars have an exit aperture of 7.14 mm (50:7), and 10 x 70 binoculars have a 7 mm aperture (70:10)
The greater the aperture diameter, the brighter and clearer the vision.
Thus, there are design differences in optical systems, and in light transmission due to the lens coatings.
There are several systems for adjusting clarity according to your own visual acuity. Individual eyepiece adjustment helps obtain maximum clarity. Most common on marine binoculars, this simple method is well suited for observation to infinity.
For hiking applications where one wants to use binoculars to see closer subjects, adjustment is handled more simply through a centre thumb wheel. It simultaneously adjusts both visual channels with the same precision.
For more than twenty years, Fujinon has produced image-stabilized binoculars for large institutions such as the army, customs, navy, etc...Now, on the strength of this experience, Fujinon offers digitally stabilized binoculars.
With this stabilization, light from the image does not diffuse over your retina. The gain in brightness is immediate and upends all the common thoughts in this area: it is as if you are using binoculars with 80 mm lenses. For astronomy, it is absolutely remarkable. For marine and hiking usages, it allows usage of high magnification binoculars without movement and bounce defects. The new Fujinon image stabilization technology
The technological innovation in Fujinon Techno-Stabi binoculars consists of the fact that the prisms are on mobile supports that can be moved at very high speeds by two servomotors, one for horizontal compensation and the other for vertical compensation. Each motor is digitally controlled by piezoelectric vibration sensors. As soon as one of them detects vibrations or movement, the signal is transmitted to the microprocessor that instantly actuates the motors to counteract the detected movement.
This technology helps achieve a professional degree of image stabilization of +/- 5°, even without gyrostabilization and at a more competitive price. The new Fujinon Techno-Stabi binoculars not only help compensate for muscle tremors, but also the oscillations and significant vibrations encountered on all terrain vehicles, in helicopters and aeroplanes, or on ships.
Lens coatings and quality:
The prisms in all Fujinon binoculars are cut from high quality Bak4 glass, which helps optimize contrast for a high definition image.
There is another very important factor in judging binocular quality: this is the light transmission of the lenses and prisms. This largely depends on the coating, which contrary to what one might think, is not just to protect them. It is designed to reduce reflections and increase light transmission. The lenses on all good binoculars are coated, but the difference is in the quality of the coating.
At Fujinon, all binoculars have a multi-layer coating and the prisms are coated in phase.
Additionally, the lenses and prisms in the SX series are coated using the exclusive EBC (Electron Beam Coating) patented by Fujinon. This process ensures an overall light transmission index of 95% across the entire visible spectrum. To truly appreciate this value, it is important to know that other binoculars only rarely approach it. Additionally, this process greatly improves salt resistance. The EBC coating consists of thirteen layers of zirconium oxide vaporized at 2700°C by an electron beam in a vacuum chamber. One of the best coatings on the market for reducing the amount of light interference and increasing image clarity. The coating reduces light loss and guarantees bright, detailed images.
(Light transmission cost for Fujinon 7 x 50 MT-SX binoculars. The high values are greater than the average for all wavelengths. Vision using Fujinon binoculars can be up to 15% more luminous than with the comparison model).