Which Extender?

[chouglez]

I have recently bought a 70-300mm Siggy and wanted to know if I can use an extender either 1.4 or 2.0 to extend the focal lenth?

 

[RobertP]

Found in one of StewartR's posts...

http://www.sigma-photo.co.jp/english/support/faq/condaitr.htm#02

Don't see your lens in the list so you'd better wait for someone that actually knows the answer

 

[percymon]

You probably can use one, but its more normal to use extenders on prime lenses.
You'll lose one stop with a 1.4x and 2 stops with a 2x - OK for wildlife in bright light (safari), but not much use for motorsport.

 

[StewartR]

I have recently bought a 70-300mm Siggy and wanted to know if I can use an extender either 1.4 or 2.0 to extend the focal lenth?

Did it come with a manual? Have you read it? What does it say?

 

[Graham_P_Clarke]

Neither the Sigma nor Canon will fit, some of the others will but you will lose 1 stop on a 1.4x and 2 stops on a 2x, this will mean you loose AF and will also lose IQ.