Vivitar Automatic Tele Converter 3x-8 for M42 brand_Kawauso-Shoten not the "BC" version with

not the "BC" version with a corner-darkening mask

The Sony FE 35mm f2

but the long rear flange will interfere with full-frame SLR mirrors- so keep it away from your 5D

plus a handy lever action system that draws in the slide mounting plate

cover your bottom

Vivitar Automatic Tele Converter 3x-8 for M42 brand_Kawauso-Shoten not the "BC" version withMost teleconverters only double your focal length; this one triples it. 3x is 50% better than 2x! Everyone will be impressed with your new teleconverter and you will become famous as the person with the most teleconverted lens. We cant guarantee that any of that is true, but what if it was? Wouldnt that be something? This teleconverter works on M42 lenses and bodies.