[Matt Hunt]

Hi

I am using the Sigma 2xTC on the 100-300mm f4 and find I am getting acceptable results but having manual focus only is hard on moving objects (so far I've tried birds and Spitfires!). Having said this, I am wondering if this is a lens focusing issue at infinity since using the converter at less than 300mm has produced results.

For this combination there are no clearance issues.

Hope that helps.

Matt