Among the Bushnell H20 series the 8×42, 10×42 and 12×42 are the most popular, with the Porro prism designs considerably more popular than the roof prism designs. There’s a good reason for this: Roof prism binoculars this cheap simply cannot deliver the same quality image as the Porro prism binoculars can. To aggrevate the problem, these roof prisms do not have phase-correction coatings, which is necessary for all roof prisms to cancel out color abberations. Porro prisms do not have the same color abbertion problems, so phase-correction is not needed.
Bushnell H20 Roof vs Porro
As can be seen in the table below, the roof prism H20 binoculars beat the Porros in two aspects: As can be expected, they are more compact and thus slightly lighter than their counterparts; they also have better close focus abilities.
The Porros, on the other hand, deliver sharper images in this price range and have better 3D vision, which come with the design. They also have better field of view. As a matter of fact, the Bushnell H20 8×42 boasts an exceptional 8.15 degree angular and 427.88 ft at 1000 yards linear field of view.
Bushnell H20 8×42 vs Bushnell H20 10×42 vs Bushnell H20 12×42
Obviously, binoculars going for less than $100 will have their limitations, but looking at all the reviews it is clear that people are very satisfied.
The Bushnell H20 10×42 is very popular, as can be seen in the numerous reviews on Amazon. , but that goes for the very popular Bushnell H20 8×42 as well (see reviews at Amazon). As a matter of fact, that applies to the Bushnell H20 12×42 as well!
The 8×42 binocular is generally regarded as the most versatile binocular and the best choice for birding. There are many reasons for this, but the most important is the fact that a magnification of 8x is just about the highest anyone can handle with ease. The higher the magnification, the more difficult it becomes to handle a pair of binoculars, since any movement by the user is amplified. This means that a 10x will be more difficult to handle than an 8x; handling a 12x is quite difficult and some people will find it impossible to use without a tripod. The higher the magnification, the more difficult to spot a moving object like a bird and the more difficult to follow it. The difficulty increases the closer the object gets, so one can understand why an 8x binocular is preferred to a 10x or 12x when viewing birds.
On top of the problem of amplification of movement is the fact that higher power always comes at a price as far vividness of image is concerned. Magnification uses some of the light entering the objective lenses, so the higher the magnification, the dimmer the image. The exit pupil has the final say in this matter. The exit pupil (the cone of light entering the eyes) is 5.25 in the case of the H20 8×42, 4.2 in the case of the H20 10×42 and only 3.5 in the case of the H20 12×42. This will not be a problem in bright daylight, but as the sunlight begins to fade (or in any overcast condition or before dawn) the smaller exit pupils will prove to be a problem, not letting through enough light for a clear image.
Field of view is also restricted the higher the magnification. The Bushnell H20 8×42 has a FOV of 427.88 feet at 1000 yards, the H20 10×42 346.5 feet and the 12×42 only 288.75 feet. This means that finding an object and following a moving object becomes increasingly difficult as magnification goes higher, since the field of view becomes smaller – on top of problems associated with the amplification of movement associated with higher magnification, discussed above.
Finally, a matter seldom discussed in this regard is the impact of higher magnification on depth of field. The higher the magnification, the more one has to adjust the focus when the object moves towards you or away from you. The closer the object you’re viewing, the bigger the problem.
All in all, in this price range you have to go for the Porro. Furthermore, the Bushnell H20 8×42 Porro is recommended above the 10×42 and 12×42. However, I have all three of them and find the higher magnification under certain curcumstances preferred to the 8×42. The Bushnell H20 10×42 will not be a problem if you have a steady hand, but think twice before you go for the 12×42 without a tripod.
Bushnell H20 10x42
|Model||Bushnell H2O 8x42||Bushnell H2O 10x42||Bushnell H2O 8x42 Roof||Bushnell H2O 10x42 Roof|
|Lens diam. (mm)||42||42||42||42|
|Exit pupil (mm)||5.25||4.2||5.25||4.2|
|RBI: Relative Brightness||27.56||17.64||27.56||17.64|
|Eye relief (mm.)||17||16||17||17|
|Angular field of view (FOV)||8.15 deg.||6.6 deg.||6.9 deg.||5.8 deg.|
|Linear FOV (m./1000 m.; ft./1000 yds)||143 m. / 427.88 ft.||115 m. / 346.5 ft.||121 m. / 362.25 ft.||102 m. / 304.5 ft.|
|Close focus (m./ft.)||5.5 m / 18.04 ft||4.6 m / 15.09 ft.||3.6 m / 11.81 ft.||3.6 m / 11.81 ft.|
|Prisms||BaK-4 / Porro||BaK-4 / Porro||BaK-4 / roof||BaK-4 / roof|
|Weight (gram/oz.)||770 g. / 27.16 oz.||765 g. / 25.87 oz.||709 g. / 23.98 oz||709 g. / 23.98 oz.|
|Fogproof: Nitogen filled||yes||yes||yes||yes|
|Warranty||5 years||5 years||5 years||5 years|