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目前能查到的资料英国生产后，后续授权给了德国的禄莱和俄罗斯的BELOMO公司生产民版。有段国外原文资料可以作为参考看看。Avimo Binocular Prismatic, General Purpose (Land Service L12A1) 7X42
Manufacturer/Model: Avimo Binocular Prismatic, General Purpose (Land Service L12A1) 7X42
Field of View: 7 deg = 124 yd/1,000 yd; APFOV 49 deg
Weight: 1,222 gr (including neckstrap, filters in pouch, and eyelens protectors)
Exit Pupil: 6 mm
Notes: Going into the 1970’s the British armed services still used circa WW II binoculars most of which were introduced before the war and some even before WW I. In 1971 a Statement of Requirement was issued for the development of a general purpose binocular usable by the Army, Navy and Air Force. Ross won the contract but shortly afterward went out of business, the contract passing to Avimo Ltd. which took over Ross in 1975. The result was the Avimo Binocular Prismatic, General Purpose (Land Service L12A1) 7X42 which was first issued to the Army in 1979. The optical components of the binocular were probably made in Singapore, and the binocular was used by the British in the 1982 Falklands War
Iraq and most recently Afghanistan. During the Falklands War it was reportedly not popular with soldiers because: 1) the objective barrels were located at the bottom of the binocular causing a soldier to risk raising his head 2 cm higher when observing than when using a conventionally built one; and 2) the binocular was prone to collimation loss resulting in soldiers separating the two halves in the field (easy to do) and using them as monoculars. The Avimo 7X42 has single layer coated optics and a reticle in the right eyepiece. It has cemented Porro I prisms like the contemporary U.S. Army M19 7X50 but unlike the M19 is of a conventional and relatively simple optical design with achromatic doublet cemented objective lenses and 3 element/ 2 lens oculars It has four ports for nitrogen purging, and its joints are O ring or rubber gasket sealed. It is supplied with two neutral density filters in a pouch attached to the neckstrap and two eyelens protectors attached by cords which can be clipped to the strap when not in use. The focus is fixed at a -1 dioptre setting which WW II studies had shown is optimal for viewing under lowlight conditions. The binocular is collimated by adjustable eccentric bushings in each of the center hinges
View 3 is the Avimo company's schematic drawing and description of the binocular:
Although most of the description is straightforward and sensible, paragraphs 3 and 4 covering collimation are confusing f. ex. the statement, “A further advantage is that the vergency tolerance is not as critical when compared with conventional instruments having parallel axes”, is unusual and seems contrary to universally accepted principles of collimation. When this much-used example was received it was slightly out of focus for my eyesight, and a sun images test showed it to be out of collimation. I was able to adjust focus by loosening the Allen-head grub screws securing the objective cels and then using a bladed spanner wrench to screw the cel in or out to the desired focus. The cel turns tightly because it is O ring sealed. Focus can also be adjusted by turning the ocular cel, but this is difficult because the cel is secured inside the binocular by two grub screws which are accessed only by removing the prism cover. Although it’s written that the Avimo resists collimation, collimating this example was likewise fairly easy. To collimate, first loosen the large Allen screw in each hinge which secures the center eccentric bushings. Once loosened, these screws instead of being removed should be gently tapped downward to disengage a small cylindrical wedge they screw into and which when the screw is tightened pulls the wedge upward firmly against the eccentric bushing fastening the bushing in place. Once the wedge is thus disengaged the eccentric bushings can be turned for collimation. The bushings in this example showed evidence of having been at least once re-adjusted which is possibly why the binocular was out of collimation. Collimation could also have been lost if a prism assembly shifted even slightly. At any rate, through a trial and error process using the sun images method to adjust the eccentric bushings in the hope of at least achieving an IPD 60 mm conditional alignment, I found that once aligned at IPD 60 mm, the binocular happened to also be aligned at both 55 mm and 75 mm i.e. collimated.
Once it was focused and collimated, optical performance proved excellent. Most noticeably the view is remarkably bright for single layer anti-reflective coatings due in large part to the binocular having relatively few light reflecting optical surfaces because it has cemented prisms and only a three lens (one objective plus two eye lenses) optical arrangement .
Also, the view is very color neutral with good sharpness toward the edge. And the ergonomics are good: it is comfortable to carry and hold; the rubber “blinker” type eyecups block extraneous light, are comfortable against the face and afford eyeglass wearers lots of eye relief enabling them to easily use the binocular; and the eyelens protectors are conveniently located and effective in inclement weather.Although apparently well-built, soldiers’ reports of its loosing collimation under service conditions indicate a problem. The eccentric bushing build is such that once the bushings are secured they are seemingly impossible to move so this is probably not the cause. As mentioned, collimation could be lost by a slight shifting of the prism assembly which is possible, but if this were the case you’d expect that collimation could be restored by adjustment of the eccentric bushings which according to reports is not the case. However, a likely cause is the two long and thin objective hinge flanges
which appear susceptible to being bent by a severe blow and if occurring would certainly throw off collimation and probably make re-collimation impossible.
A civilian model of this binocular in both rubber and non-rubber armoured versions was made under license by the German Rollei Company and a rubber armoured version is still manufactured by the Russian BELOMO company.
See View 6 for a disassembled Avimo 7X42 showing its cemented Porro I prism assembly, rubber gasketed prism housing, and O ring sealed objective and ocular lens cels。 |
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IP卡
狗仔卡
提升卡
置顶卡
沉默卡
喧嚣卡
显身卡
