could be an M42 mount, bearing in mind its a Carl Zeiss Jena. If it is you can buy adapters that will allow you to mount it to your Sony A300. If you buy one with an autoconfirm (
http://cgi.ebay.co.uk/Adapter-Mount...39:1|66:2|65:12|240:1318&_trksid=p3286.c0.m14)
then whilst it won't autofocus for you, when you turn the focus ring it will tell you in the viewfinder if its in focus or not.
You will also have to set the aperture on the camera in aperture priority or manual mode, then manually turn the aperture ring on the lens to the same value as set on the camera (aka stop down metering). Other than that, provided its an M42 mount, it'll work, and probably give you a damn fine image
that could stand for Multi Coated, the M42 super takumars have SMC written on them for super multi coated. And the old minoltas are MD/MF mounts, not MC.
Right I'm off to google
right a very quick google reveals that possibly its not a minolta mount at all:
http://photo.net/sony-minolta-slr-system-forum/008Gxc
I can't seem to find any reference to a CZJ 75-300mm MD/MF mount. So MC stands for Multi Coated.
And this popped up on ebay:
http://cgi.ebay.co.uk/ws/eBayISAPI....009164&cguid=e606097b11c0a0e202460426fffe4f5b
CZJ only made primes for M42 mounts, so its not an M42 mount like I first thought, unfortunatly. Its more than
likely a Canon, Nikon, Pentax or Olympus mount (old school ones)