01-23-2019 11:21 AM
"... I could use my Canon 2x Extender with the Sigma lens."
Why not use the Sigma tel-con with the Sigma lens. Certainly a person that buys a $3500 lens can buy the correct extender?
I have one for my 120-300mm and it works. I don't like it but it works. I don't like tel-cons in general, however. I have not tried it with my Canon tel-con.