KMZ Crystal Rifle Camera for the Hunt for Unknown Objects, c. 19

KMZ, USSR. Crystal No. 61022994, SLR for 24 x 36 mm, with grey hammered paint effect, rifle mount in corresponding finish and an indirect zoom lens, shutter working. – Note: A scientific rifle camera for Unusual Flickering Objects that would otherwise appear blurred. The camera was presumably built as a prototype for scientists in Akademogorodok, to document insects or plants quickly, conveniently and undisturbed, as well as for researchers who need to focus objects far beyond infinity (optical cloaking) and are not disturbed by the inverted image in the reflex viewfinder. The camera is fitted with an indirect zoom lens, the negative element is fixed and there is no structural focusing option. The only movable part is the positive element, a Petzval type 2/12 cm no. 063270, which is far away from it. It is the only element that controls the lens by means of the stroke of the slide rod (51 mm stroke). Without stroke, the macro range is 1:1 at a distance of 65 cm from the front lens. With a stroke of 28 mm, infinity is reached with a focal length of approx. 500 mm. Then, structurally, there is a further stroke of up to 23 mm for considerable scope far beyond infinity, more than any known infrared index. Due to its design, the lens aperture is at its weakest at infinity; at close range the light intensity increases significantly due to the shortening of the focal length. The addition of an iris diaphragm is unnecessary. The image quality (checked with a strong magnifying optics in the film window) is of high color purity and sharpness.

布雷克拍品等级是为了方便竞买人判断拍卖品的成色而设置的。布雷克等级用1到6级来标注外观和功能的成色，(从非常好到非常差)。 在目录图册里用括号里的2个数字来表示，前一个数字表示外观成色的级别，后一个数字表示功能成色的级别。如(3/2)表示外观成色是3(满意的)，功能成色2(好)。 成色 定义参照下列标准： 1 - 非常好 (未使用过，没有使用痕迹) 2 - 好 (新，极少的使用痕迹) 3 - 满意的 (普通的使用痕迹) 4 - 及格的 (明显的使用痕迹，某个非主要部件是后配的) 5 - 有缺陷的 (极明显的使用痕迹, 某个主要部件是后配的，功能上有缺陷，需要修理) 6 - 非常差 (严重破损, 缺少重要部件)