Binoculars review

Ecotone AD-7 10x42

Ecotone AD-7 10x42
4 January 2010
The next suggestion coming from the Polish Tri-Cities area Ecotone company, which, on account of its light physical weight and small dimensions, is designed mainly for ornithological and tourist purposes. The AD-7 series includes the following models: 10x42 and 10x50.

The AD-7 10x42 model, tested by us, is a set of roof binoculars which prisms are coated with aluminum and covered with P layers (Phase coatings). Those layers eliminate contrast loss and interference effects near the edges of roof prisms.

The binoculars’ housing is made of aluminum, covered by high quality rubber and nitrogen-filled. All air-to-glass surfaces are covered by high quality antireflection coatings. The equipment is waterproof.

  • Lornetka Ecotone AD-7 10x42
  • Lornetka Ecotone AD-7 10x42
  • Lornetka Ecotone AD-7 10x42
  • Lornetka Ecotone AD-7 10x42
Manufacturer data


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Magnification Lens diameter Angular field of view Prisms Eye relief Weight Price
10 42 105/1000(6o) BaK-4/roof 15 mm 750 g 972 PLN
Results of the review
Real front lens diameter Left:   41.98+/- 0.05 mm
Right:  41.96+/- 0.05 mm
8 / 8.0 pkt
Real magnification 9.6+/- 0.3x 2.5/3.0
Transmission 79+/- 3% 9/25.0
Chromatic aberration Medium in the centre, high at the edge. 4.5/10.0
Astigmatism Slight. 7/10.0
Distortion The distance of the first curved line from the field centre compared to the field of vision radius: 45% +- 6% 5/10.0
Coma Low. 7.1/10.0
Blurring at the edge of the FOV The blur occurs in the distance of 83% +- 5% from the field of view centre. 6/10.0
Darkening at the edge the FOV Slight but noticeable. 3.8/5.0
Whiteness of the image Natural. 4.3/5.0
Collimation Exemplary. 5/5.0
Internal reflections
Left: Right:
Ecotone AD-7 10x42 - Internal reflections - Left Ecotone AD-7 10x42 - Internal reflections - Right
Housing Light and handy. It is comfortable to hold and to look through. A bit of plastic near the objectives. The rubber on the objectives moves a bit. 6.5/8.0
Focusing Central screw moves smoothly and comfortably. The full range needs a 450-degree turn. The focusing on right eyepiece works smoothly but not comfortably. It might be difficult in freezing conditions. 3.8/5.0
Tripod There is an exit but a bit difficult to access. 2.5/3.0
Interpupilary distance from 58.5 to 74.2mm 5/6.0
Closest focusing distance 1.65-m. 2/2.0
Eyepieces FOV Apparent field of view of 58.4 deg (according to simple formula) and 54.0 deg (according to tangent formula). 10/20.0
Field of view Measured by us amounted to 6.08 +- 0.03 degrees and it was by 0.08 degrees wider than in the specifications. 5.5/8.0
Quality of the interior of the barrels Black inner tubes but shiny. Gray bottom. Clean. 4/5.0
Left: Right:
Ecotone AD-7 10x42 - Vignetting - Left Ecotone AD-7 10x42 - Vignetting - Right
Egg-shaped pupils.
OL: 2.1%, OR: 0.9%.
Prisms quality High quality BaK-4 . 8/8.0
Antireflection coatings Greenish on the objectives and prisms. Green-pink on the eyepieces. Low intensity. 5/5.0
Warranty [years] 5 3.5/6.0
Final result
37th place in global rank of our test of 10x42 binoculars.
127.2 / 190 pkt
Econo result 11th place in Econo rank of our test of 10x42 binoculars. 7.1pkt.


  • handy and solid casing,
  • most of the field of view sharp,
  • slight coma and astigmatism,
  • good whiteness rendition,
  • sharp image already from 1.65 meters,
  • good quality BaK-4 prisms,
  • good coatings.

  • distinctly truncated pupils,
  • distinct chromatic aberration at the edge of the field of view.

In the next stage of the 10x42 binoculars test five very similar instruments competed against each other. In alphabetical order these are as follows: the Bynolyt Buzzard SHR, the Ecotone AD-7, the Fomei Diplomat, the Opticron Verano and the Vixen Apex Pro. The chart below shows a comparison of properties and prices of those instruments.

As you see, the parameters of these binoculars are almost identical. All of them are small, handy and light constructions of practically the same weight and the same dimensions and identical field of view. Their exteriors don’t differ either as can be seen in the photo below.

The weight differences are so small we can suspect in every set of binoculars an identical optical system was used in the sense of the number of elements and groups. The instruments can differ slightly when it comes to the eyepieces’ construction which might be suggested by minimal differences in eye relief values, changing from 15 to 17 mm. What’s more, the binoculars have certainly different coatings which is clearly visible if you just glance at their colours and intensity.

When it comes to the score in the test the binoculars occupy exactly the same quality segment. All of them got about 123 points and the difference between the best and the worst amounts to only 2.5 points. It is really not much because 2-4 points constitute the estimated summary error of our testing methods. From the statistical point of view the score differences are practically negligible, although they lead to interesting conclusions.

Common traits of all the binoculars are quite visible. Because of small dimensions the prisms distinctly limit the light access through egg-shaped pupils. That effect is bigger for the left pupil. Short and small construction is also the source of problems with chromatic aberration correction. The eyepieces with the 60-degree-wide field of view don’t show sharp images to the very edge and about 20% of the field is visibly blurred. The binoculars’ transmission level is not impressive (apart from the Buzzard) because of the light loss on vignetting pupils and aluminum coatings on the prisms (only the Bynolyt used better SHR coatings).

It’s worth noticing that the Vixen, which is the cheapest, fared the best of these five devices. Vixen is a Japanese company after all and its factory is also situated in Japan. If you are close to the factory you can control it efficiently and cut costs at the same time.

One of the most expensive binoculars here is the Bynolyt Buzzard. The higher price can be justified by using special coatings on the prisms which enhance transmission (SHR). The test score seems to confirm it fully. In categories connected with the coatings (transmission, flares or coatings) the Bynolyt fares significantly better than the competitors although it wastes that advantage in other categories. If you consider transmission and a long guarantee period to be very important features the Bynolyt will be an excellent choice.

The next interesting suggestion is the Ecotone AD-7. Its score is the worst in this group but the price/quality ratio undoubtedly the best. Certainly it is a product worth pondering.

Perhaps the most difficult positions occupy the Fomei Diplomat and the Opticron Verano. For a really significant amount of money, compared to their rivals they offer nothing more than good guarantee conditions. When it comes to the optics and build quality their level is exactly the same as that of twice cheaper instruments from Vixen and Ecotone. Opticron Verrano is a bit lighter and it might be also a serious asset.