Summary
Pros:
- compact and solid body,
- sensibly corrected chromatic aberration,
- slight astigmatism,
- low distortion,
- small light fall-off on the edge of the field,
- wide field of view,
- good quality glass BaK-4 prisms,
- circular exit pupils,
- dark and clean inside the tubes.
Cons:
- average transmission,
- huge coma,
- noticeable resolution decrease on the edge of the field of view,
- no coatings on one air-to-glass surface of the objective,
- field of view a bit narrower than that declared in the specifications.
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The Action EX series binoculars are models which you can recommend on spec for beginners. If anybody is looking for a pair of binoculars which don’t cost more than 100 USD and asks my opinion I don’t put forward any Action VII device or one of the Aculons but I suggest that you should increase the budget by couple of USD and get interested in one of the Action EX instruments. If you are used to cheap optics which can be bought at any market place the Action EX class binoculars most of the time will be advanced enough to make a very good impression and it’s hardly surprising – these are classic Porro devices with achromatic objectives, designed by a company which is a binoculars specialist few manufacturers could rival. Their products have been present on the market for a long time and their sales volume has been significantly high; that’s why the price is sensible and the price/quality ratio – very good.
 Nikon Action EX 8×40 CF and Olympus EXPS I 8×42
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Additionally, because of the roof prism binoculars trending, the competition in this segment is becoming scarcer and scarcer. By and large any sensible options are offered only by such companies as Bresser, Bushnell, Delta Optical, Fomei, Olympus, Opticron, Pentax or Praktica. Still none of these producers can offer such a rich choice of parameters as the Action EX series; mind you their products are often worse when it comes to some features (e.g. compare the fields of view of both pairs of binoculars which are presented in the photo above).
If you focus solely on 8×40 (8×42) Porro devices which cost about 500 PLN (about 150 USD) the choice is even narrower.
The following chart
shows models which you can buy without any problems in Poland.
Small wonder the Nikon Action EX 8×40 CF is a pair of binoculars which are mentioned very often in discussions on our website. To tell you the truth I am ashamed it took me so long to test it.
Let’s progress to the results of the test. I can say the resolution graph surprised me the most – it is presented below.
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For a Porro device those results are weak, especially if you compare them to the performance of the Action EX 10×50 CF, tested several years ago. You would expect that the binoculars should exceed the 90% levels, not just sneak near 80%. If you look closely at the coatings you’ll discover the reason behind low resolution values. It seems that one air-to-glass surface in the objective is not covered at all and the prisms and one part of surfaces in the eyepiece are covered by just cheap one-layer coatings. Such an economy is hardly understandable, especially when your rivals, like the Olympus EXPS I, can perform much better. It is also strange because of the results of the Nikon Action EX 10×50 CF, tested several years ago, which had multi-coatings on all air-to-glass surfaces and the transmission on a level of 90%.
As we are mentioned the slip-ups we must also say something about that field of view, a tad narrower than declared (the same flaw we found in the 10×50 model), high coma and the distinct resolution decrease on the edges.
However, in order to keep our review nicely balanced, you should also mention many strong points of the Nikon Action EX 8×40 CF. You can praise its wide field of view, well-corrected when it comes to the distortion, chromatic aberration and astigmatism; its workmanship is also of high quality, with a solid casing, good darkening and cleanliness inside the tubes. Nice, circular exit pupils and good quality prisms should be mentioned as well.
The parameters of the tested binoculars and its final score in our test confirm the high opinion the Action EX series enjoys and the feature it is famous for, namely its good price quality ratio. The immediate rivals such as the Delta Optical Titanium 8×42, the Olympus EXPS I 8×42 or the Pentax PCF II 8×40 WP might have better testing results but their fields of view are narrower so easier to correct. If the size of the field of view is important feature you are looking for the Nikon Action EX 8×40 CF will live up to your expectations.
