https://community.usa.canon.com/t5/EF-RF-Lenses/extenders-doubler-for-us-old-folks/m-p/13447#M20771 <P>I have a 5d Mark ll and am interested in an extender (doubler for us old folks) and is it true thatthere are compatability issues? There are only certain brands and / or&nbsp; models that I can use w/ this camera?</P> Mon, 04 Feb 2013 20:58:29 GMT MMStar 2013-02-04T20:58:29Z https://community.usa.canon.com/t5/EF-RF-Lenses/extenders-doubler-for-us-old-folks/m-p/13447#M20771 <P>I have a 5d Mark ll and am interested in an extender (doubler for us old folks) and is it true thatthere are compatability issues? There are only certain brands and / or&nbsp; models that I can use w/ this camera?</P> Mon, 04 Feb 2013 20:58:29 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/extenders-doubler-for-us-old-folks/m-p/13447#M20771 MMStar 2013-02-04T20:58:29Z https://community.usa.canon.com/t5/EF-RF-Lenses/extenders-doubler-for-us-old-folks/m-p/13467#M20772 <P>The most common name for them now seems to be Teleconverters (TC's). This is the best source of info I know about them.</P><P>&nbsp;</P><P><A target="_blank" href="http://photography-on-the.net/forum/showthread.php?t=457299">http://photography-on-the.net/forum/showthread.php?t=457299</A></P><P>&nbsp;</P><P>Make sure you understand the effect using a TC has on the AF system.</P> Mon, 04 Feb 2013 23:30:55 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/extenders-doubler-for-us-old-folks/m-p/13467#M20772 cicopo 2013-02-04T23:30:55Z https://community.usa.canon.com/t5/EF-RF-Lenses/extenders-doubler-for-us-old-folks/m-p/13661#M20773 <P>My advice is avoid them but if you have to, the Canon 1.4 is the best. But you need to see the lens' it is compatible with and works best with.</P> Wed, 06 Feb 2013 17:39:00 GMT https://community.usa.canon.com/t5/EF-RF-Lenses/extenders-doubler-for-us-old-folks/m-p/13661#M20773 ebiggs1 2013-02-06T17:39:00Z