Adapter M42 to Nikon

Дали некој има искуство со вакви адаптери?
Како што читав на интернет се јавуваат и одредени проблеми?

For using Nikon cameras with M42 lenses (Praktica, Zenit). It is impossible to compensate flange bases difference without using an additional back lens. As a result, the picture quality becomes worse. So metric scale M42 doesn’t keep its meanings and focusing can’t be to infinity.

You should remember that extension ring doesn’t work, diaphragm control is set manually. This adapter can work with lenses having both only automatic diaphragm (A) and selector A/M (automatic/manual diaphragm). It is possible to use Macro rings and other accessories. Approximate focal lengths: 50mm-1,5m; 85mm-3,5m; 135mm-6m.

Има разлики од адаптер до адаптер?? Цените на интернет се движат од 2$ до 25$

http://search.ebay.com/M42-Nikon-adaptor_W0QQ_trksidZm37QQfcidZ209QQgbrZ1QQsaveZSave

Да не знае некој дали се продава вакво нешто низ Скопје?