Originally posted by Christopher Finch Na Horuk - how would I tell the difference?
This only applies to old lenses, from back when Germany was in two parts. Zeiss aus Jena (or something like that) is Eastern and not quite as great as the Western stuff. These lenses usually also say "Made in.." somewhere on them. But if the lens is a modern Zeiss, then its probably good in terms of build and IQ. You can also check out the lens reviews on this sire.
And the K-01 would actually be a nice Pentax body for m42 lenses. High quality 16MP sensor, very low AA (which means sharper photos), has focus peaking (great for manual focusing), good metering with manual lenses (doesnt have to move mirror to meter/preview).. and you can get it super cheap with a great 40mm prime. Just sayin
Edit: Just get an adapter without a flange, so you keep infinity focusing. No point in using a flanged adapter to short contacts on a mirrorless.