Pentax is a brand of excellence for its product range of cameras, lenses, sports optics, life care products and the security systems. They offer models with high optics and its recent release is a new DSLR that is an advanced model in its product range. In the sports optics category you could find wide range of binoculars with different features, technical, size, design and applications. The following is the review of Pentax Jupiter III 8×21 Porro Prism Binocular which is known for the compact and light weight design.

Pentax 8x21 Jupiter III Binocular

Model Overview:

This 8×21 Jupiter III Binocular model in its compact dimension of 115mm in height, 83 mm in width and 30 mm in depth makes it an easy one to hold and carry. It weighs mere 160 grams to be known as the light weight model. This is one of the prime criteria for the many users to decide on the product. Pentax makes it more interesting for the user to choose among the 3 available colours of black, silver and blue. Particularly petite in size, attractive in design and efficient in performance makes it worthy in the first hand. It allows the user to use this binocular in different occasions like the sporting events, concerts, traveling and hiking as well as for the general outdoor. The full body design and the convenience eye cups also with the diopter adjustment make it the one to stand out from the crowd.

Prism and Lens:

Pentax Jupiter III 8×21 Compact Binocular belongs to the Porro prism type and is enriched with the BaK 4 type of prism. It gives the advantage of multi coating, built-in lenses that are designed exceptionally well and highly functional with the high contrast levels and the bright viewing experience. The advantage of multi coating is that it prevents the inner reflections and the light loss of the binocular. It is also been accounted that about 40% of the light loss can be prevented for the maximum.

Objective lens and the Magnification:

More universally the magnification of the binocular is referred in the model name and this model is said to offer 8 x magnifications which means that it makes the objects appear 8 times bigger than its original size. While the second number that is denoted in the model name is the aperture which is 21 mm for this particular model. This is the objective lens diameter and the size of the objective lens is important for the function of the light gathering ability.

Pentax Jupiter III 8x21 Binocular Blue

More technical details:

  • The field of view at the distance of 1000m is known to be 123m which denotes the width of the field of view that is the width of the area in metres that can be viewed in the binocular.
  • The exit pupil which is 2.62 mm for this model indicates the size of the small circle present in the objective lens. It supports the lens in the light gathering, the higher is better for the image brightness.
  • Eye Relief accounts to be 10mm which is technically the maximum distance present between the ocular lens and the eye. The longer is better and in a way it comforts those with the correction lens. This device offers a nominal eye relief.

Other product details:

This model allows a great close focus that can go for the minimum distance of 3.5 m making it a suitable model to view the moving objects and hence delivers a great result for the sports, birding and wild life too. The eyepiece rings are made of rubber material that is soft on eyes and is a stress free design.

Pentax Jupiter III 8×21 Light Weight Binocular is both functional and attractive giving the power of magnification in the hands of the desired along with the accessories like the case, strap and the cleaning cloth.

Pentax 8×21 Jupiter III Binocular – Technical Specification Table

Manufacturer Pentax
Model Name Jupiter III 8×21 Binocular
Prism Type Porro Prism
Magnification 8x
Diameter of Objective Lens 21 mm
Exit pupil 2.62 mm
Weight 160 grams
Field of view at 1000 (meters or yards) 123 m
Available colours Black, silver and blue
Close focus 3.5 m
Eye relief 10 mm
Eye piece rings Rubber
Design Compact and light weight
Application Sporting events, concerts, hiking and traveling
Accessories Case, strap and cleaning cloth

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