EF 70-300mm f/4-5.6 IS USM lens.

[gallagherjb]

I have a 60D camera and I just purchased the EF 70-300mm f/4-5.6 IS USM lens because I thought it might be a good addition to give me a bit more reach than my 18-135mm. I noticed, in AF, the zoom will not fully retract. If I switch to MF I can retract the zoom completely. It's not like the zoom is extended a lot, maybe 1/16-1/8 inch. Also, is it normal to hear the motor sound often...my other lens is not an USM model so I'm not sure if this is normal.

I'm fairly new to photography, so please forgive any of my technical incompetence.

Thanks in advance for any help or insight.

[Skirball]

Is it attaining focus?  If so then everything sounds normal.  There is a little extra travel on the focus on both ends.  They put that in so that the mechanism doesn't slam against the stop when autofocusing at the ends (e.g. focus at infinity, or the minimum focus distance).

[gallagherjb]

It is attaining focus. I just got it yesterday so I haven't had much time to play with it...other than a quick operational test.

Thanks for the info.

[bobakman]

Focus and zoom are separate functions you may be confusing the compound (Rotational and Linear) movement of the focus with the simple in/out linear movement of the lens barrel during Zoom. Referencing your statement: "If I switch to MF I can retract the zoom completely." are you rotating the focus ring  or  zoom ring when you do this? FYI total focus barrel distance on my same lens is 5/8". Also make sure that your zoom lock is not engaged it's a little slide switch on the side of the lens.
Lastly if you had AF enabled and then switch to MF the focus would be at it's last AF point that the camera told it to be which may or may not be fully retracted.
Hope this helps.

 My lens does make some sounds during focus and during IS definetly not as quiet as my STM lenses.

Bob