THE F-STOP DOES NOT WORK ON MY SONY A7S WITH MY METABONES EF-E MOUNT

[Victor Vandevenne]

So i bought a Sony a7s with a metabones EF-E mount. But when i put my Sigma 18-35 mm f1.8 on the metabones i can not control the F-stop of my Sony?!! Help? Thanks a lot!!

[Username]

If your other EF lenses work properly 

on the MetaBones, then the particular 

Sigma lens has incompatible firmware, 

a typical problem of Sigma's reverse 

engineering to avoid licensing costs.  

   

Try a firmware update and if that fails 

to solve anything, it's a dead end.