3M-5A (f8/ 500mm) Soviet Mirror Tele Lens. A telephoto lens with a focal length of 500 mm for a number of tasks related to observation, photography, astronomy - shooting distant objects. ZM-5A is an improved analogue of the earlier MTO-500, to a large extent, the improvements affected ergonomics. Letters ZM short for Mirror Maksutov or Mirror-Meniscus, both options are correct.The letter A at the end indicates a system of interchangeable mounts. Meniscal Mirror Telephoto Lenses are a very compromise solution, where the length of the lens is important in the first place - as compact as possible. The mirror inside the lens has reduced the length by two and three times (+/-). Focal length - 500 mm. The maximum aperture is 8.0.
The number of lenses / groups is 4/3. The minimum focusing distance is 4 m.
Resolution center / edge - 40/20 lines / mm. Type enlightenment - single layer. Attachment for nozzles - M77 thread. Optics mount - "A" interchangeable adapter system (m42 / A).Actual weight -1,225 kg. It is long - 152 mm. Despite the decent diameter of the lens, the body is tailored very intelligently.
The metal cover is screwed in place of the filter, thread 77 is quite rare. In the twisted position, it does not allow the standard lens hood to extend (it is also implemented with another Tair-3A telephoto lens), and the lens hood closes the focus ring.Its ingenious and simple, you simply have to put the hood in working position. How you can replace the diaphragm rings as well as the diaphragm itself is not here. All Mirror-Meniscus (Mirror Maksutov) telephoto lenses are endowed with this special feature. Structurally, it is not possible to place it, however, with an open aperture of 8.0, you will not want to cover the aperture. Like all mirror meniscus ZM-5A has a low light transmittance, there is no exact data, but we can assume that it is within 0.6 (MS version - 0.7 and MTO-500 - 0.5). Aperture 8.0 is the physical size, but the light passes through the 0.60 lens (so as to be clearer I will count as a percentage - 60%), the loss is 40%. Such a low indicator is due to the fact that the mirror itself does not reflect all the light and the biggest losses are on it (here it is a compromise). The actual aperture formula is: 8.0 + 8.0 × (1 - 0.60) = 11.2 aperture in fact.
In the version with multi-coated MS: 8.0 + 8.0 × (1 - 0.70) = 10.4. For this reason, there are complaints in the network that the lens is "darker" than indicated on it and the shutter speed must be selected longer in comparison with lens analogues.ZM-5A has two tripod mounts for two types of threads. Taking pictures with your hands is quite difficult even on a white day; in bright weather, the ISO parameter was not set below 400. Without a good tripod, well, at least a monopod photography is extremely tiring. But the light version of the ZM-5CA tripod mount is completely absent. This telephoto lens has a universal system of interchangeable adapters "A", the native tail A / m42 can be replaced, for example, with A / Nikon.
And its really cool, but for cameras without a built-in flash, the Beak interferes. The lens does not twist tightly and rests on the "beak" of the flash, and it does not matter Canon, Nikon, Pentax. In a perfekt condition, functional. Otherwise we can't guarantee availability of it.I take our feedback seriously. I'll try do everything we can to resolve the issue. The item "3M-5A 500mm f8 Soviet Russian Mirror Tele Lens M42 like MTO-500 ZM-5A USSR" is in sale since Wednesday, November 13, 2019. This item is in the category "Cameras & Photo\Lenses & Filters\Lenses". The seller is "plotv_56" and is located in Zaporizhzhya. This item can be shipped worldwide.