I am considering a tele-extender for my Sigma 7-300 Zoom. At 70 mm, the back element is back into the mount, and moves forward as I zoom to 300 mm. What options do I have and can I preserve the AF?
John G.
I am considering a tele-extender for my Sigma 7-300 Zoom. At 70 mm, the back element is back into the mount, and moves forward as I zoom to 300 mm. What options do I have and can I preserve the AF?
John G.