So, I just got a 28-105mm Canon Lens with the Ring USM that says it is full time manual focus. While playing with it I pushed my shutter release half way, then adjusted the focus with the focus ring and pressed the shutter release all the way. The lense automatically focused back to where it was before. I am using a Rebel XT. How do I get the camera to quit trying to focus the lense when I manually overide it? Or is that not the intention of full time manual focus?

Thanks for you help!

Should be a small buttone Marked AF/MF by the lens.

If not TRY READING THE MANUAL!!!

So, I just got a 28-105mm Canon Lens with the Ring USM that says it is full time manual focus.

This lens is NOT a full-time manual focus lens, it simply has that CAPABILITY if you choose it. That's a big difference...

Yep, there should be a AF/MF switch on the barrel...

Well I would say thank you for the replies, I think.

I would read the manual, but I didn't get one with the lens. I purchased it used and that was unfortunately left out.

The lens I bought is the 28-105mm F3.5-4.5 II with USM and FTM. Both the canon web page confirms that is had that ability as well as every review of the lens I have read, to include the one on this site.

Obviously switching to MF mode would enable the lens to be focused manually, but my goal was to have AF and be able to override it without doing so.

After looking elsewhere for my answer I did find that with a DReb you need to enable custom function number 4. That will allow you to use the AE Lock button to focus. You can autofocus the lens with that button and release it then wihtout having to switch to MF mode you can rotate the focus ring manually to correct what ever you see fit and then depress the shutter without the camera re-focusing for you.

Again thank you for the replies I did recieve. I wanted to share what I had found out elsehwere so others who might have this question and didn't know where to look could find it. Of course had I received a manual with this lens I am sure that I would have taken the time to read it before I posted here, but absent as the manual is that wasn't an option. I guess in hindsight had I done my own homework I wouldn't have had to post here and receive the response I did. My bad.

Welcome to the forum Sedalia. No need to appologize for asking questions. That's what we're here for. :)