Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Canon Lenses

Thread Tools Search this Thread
Old Feb 23, 2006, 3:19 PM   #1
Junior Member
Join Date: Feb 2006
Posts: 7

I'm considering getting the Extender EF 2x II, but I don't know anything about it. Seems like a cheap way to get twice as much length, but I don't know if it's too good to be true. Their website says

With the EF 2x II, AF is possible with any EOS body if the lens has an f/2.8 or faster maximum aperture

Does this mean that AF only works if you're at 2.8 or faster, or AF doesn't work at any aperture with this if your lens doesn't have a max of 2.8?

Also, can anybody comment on the picture quality when it's used?
uberwench is offline   Reply With Quote
Sponsored Links
Old Feb 23, 2006, 4:02 PM   #2
Senior Member
Join Date: Apr 2003
Posts: 2,289

The autofocus is camera and lens combo dependent. the canon 1 series cameras will autofocus at f/8. the 20d/30d will autofocus at f/5.6 or faster. so, if you have a 20D and have a f/2.8 lens on it adding the 2X TC will still autofocus but probably much slower. If you have a 1 series camera you can put an f/4 lense on it and autofocus with the 2X TC. From what I have heard/read the 2X TC does cause a noticeable loss in image quality. With excellent quality lenses (L glass) the loss is not as greatly noticeable. If you don't mind manually focussing, you can use the 2X TC on any camera. Another thing is that any TC (1.4X or 2X) does not work very well or as well on zooms as they do on primes. hope that helps.

djb is offline   Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

All times are GMT -5. The time now is 4:08 PM.