These two binoculars were designed for military use, being fully water proof and equipped with a range reticle. Both are delivered with a nice leather case, leather rain-guard for the oculars, yellow filters and instruction manual in Chinese language. There is no rubber armor nor are there any covers to protect the objective lenses. They are offered by Hioptic (see link below), but I am not aware whether any of them have surfaced in the Western countries so far.
|of view (deg)
|of view (deg)
The specification of 7x40 is the classical size for East Block military binoculars, see for example these Warsaw Pact binoculars. The sketch displays an air-spaced doublet objective and an ocular construction using five lens elements in three groups. According to the manual, this binocular is immersible in 1.5m deep water for one hour and operational from -43 to +55 degs. Celsius. The mechanics feels fine, everything is moving smoothly and without play. The eye-relief is generous, but the eye-lens is quite a bit recessed so that the effective distance is much lower than specified. It should still be enough to be used by eye-glass wearer, however, once the soft rubber eye-cups are folded down. The design reminds on the Zeiss Jena Septarem, i.e. the civilian version of the 7x40 NVA DF (without rubber armor), but it is less heavy and apparently has smaller prisms. It is resting comfortably and steadily during hand-held observations.
The image is covering a conservative angle of 8 degs., yielding about 56 degs. apparent field of view. The brightness is moderate, with a slightly warm (yellowish) color tone. Sharpness is high in the central part and slowly degrading towards the edge, so that about 70% of the field (measured radially from the center) display point-like star images. There is some pincushion distortion visible, the panning is very smooth, making it an excellent binocular for surveillance applications. Under situations which are notoriously causing stray light, such like one hour after sunset, there is low-to-moderate response visible. The image then shows a diffuse white-out around the edge of field, that is not affecting contrast in the central region. In fact, the internal tube finish is somewhat glossy, and there is one side pupil visible, indicating a prism leakage. The latter is of less relevance, however, since with its large exit pupils there is little danger for the eye to catch stray light from these leaks. This glass is showing some ghosting when bright light sources are observed in the night, but the intensity of these ghosts remains moderate. The reticle on the right hand side produces a notorious reflex when the moon is observed. The low light performance is reasonable because of its large sized exit pupils, although the light transmission of this device is less than perfect.
In summary, this binocular provides a reasonable performance. Its multi-coating appears to be of average quality. It does not reach the performance of the Romanian 7x40 IOR-SA and is also somewhat behind the Chinese 8x40 BM20840 when coating and image brightness are considered. Its edge-sharpness is superior to both of them, but this is mostly a result of its narrower field of view. On the plus side there are a couple of excellent mechanical features. If the price of this binocular is reasonable, say below 150 US Dollars, it could well serve as a 'little man's IOR-SA'.
|of view (deg)
|of view (deg)
This high power binocular is at the limit of whatever can be steadily hand held. It comes with the same impressive mechanical specifications as the 7x40, i.e. water proof up to 1.5m for one hour and a wide temperature range within being operational. The sketch seems to indicate a rather complex ocular construction with six lens elements in four groups. The eye-relief is rather short, and the eye-cups cannot be folded - this binocular is therefore not suitable for use with eye-glasses. The moving parts are a bit stiff, so that a precise focusing can become a tedious task. Once done, the settings remain where they are, however. The weight of this glass is fairly low, and, like the 7x40, this binocular is resting nicely in the user's hands, but maximum performance is only delivered once the elbows are supported, otherwise the jitter is taking away some of its high resolution. The model I got seems to be already made some years back, in 1997, if I am not misguided by the serial no. Its coating is not state of the art, rather comparable with the single layer coatings of the 1970s. It may well be that the current version of this glass has got a much improved coating, but I have no information on that.
The image is very wide with about 72 degs. apparent field of view. Its brightness and contrast is low-to-moderate, a consequence of the mediocre level of coating. As is the case with the 7x40, the image has got a very slight yellowish tone. The central sharpness is excellent. In fact, when comparing with the 7x40, the 12x42 appears to produce the finer star images. This could as well be a result of the much narrower exit pupil and, along with that, less residual aberrations coming from the eye's pupils. The stars remain point-like up to 60% of the field, and close to the edge the aberrations are reaching a high level. This binocular displays an unusually low amount of pincushion distortion. Consequently, a rolling-ball (globe effect) is visible when panning. In twilight, this binocular is hardly affected by diffuse stray light. But once there is a bright light source located outside the field, a fan of reflections is scattering inside the field which can significantly reduce the contrast of the image. In fact, the internal tubes have got a glossy finish, and this turns ugly for such a wide angle binocular. Once the light source is shifted inside the field, an array of ghosts of moderate-to-high intensity is showing up - the consequence of an insufficiently protective coating. Keeping this in mind and accounting for the small exit pupils of only 3.5mm, the low light performance of this glass is poor.
In summary, this is a high power binocular with impressive mechanical features combined with a low weight. Since it comes with a simple single layer coating, the range of application of this glass is limited to daytime use, thereby avoiding high-contrast situations. The central sharpness is high and the field of view is impressive, but usable only without spectacles. As mentioned above, it may be that a current version of this binocular exists which has got improved coatings. Even then, I would like to see some baffles installed inside the tubes to reduce reflections which are too easily provoked by bright light sources.
Hioptic Military binoculars
Last updated: Aug. 2005