Which mirror lens would you get? The Russian (Zenitar, MC or whatever...) 1000mm/f10 in M42 mount or the Sigma 600mm/f8
I head that this 600mm Sigma is really more like an f11. If that is true I am better off with the f10 one. But it is possible that the f10 is more like f16. Also. You think I could just simply superglue a K mount converter on this? I really want to put one on permanently, not having to deal with taking the converter out all the time... L
