So then, let's say that's 21M 200/4 lens is the soviet rival of CZJ Sonnar 200/2.8.
Ok, it's NOT f 2.8. It's just f4.
But it's very sharp lens with good transmission.
If You can not afford Sonnar -nothing to worry about.
Image quality is great, stepped down to f6,7 this lens is clearly showing that nowadays it shall have "APO" painted somewhere on the body.
The main drawback - problems with aperture switch are quite common. You can end with lens without working diaphragm.
The best solution to prevent this (when the lens is ok) is to set it to manual mode and then use the insulation tape to block the switch in this position.
I recommend red tape - You will have something like Canon's L-series designation ;)
Lens is heavy, clumsy and having on mind what is written above - dependable.
Like Sonnar it's quite prone to flare when working with shiny digital sensor, so if You are going to hunt something too close to sun I recommend custom sun shield as the on-board sliding one is too short for such challenges.
I offer true 3D photography - no post-processing software tricks,
just two objective lenses and two independent imaging devices.
Available weekend sessions.
Contact me for details.
CGI - due to time limitations still only for complex scenes,
although simple animations are possible.