Focus speed (28-135mm IS Vs. 18-55mm kit)

[funpix]

I just got my 28 -135 IS and wonder if it is normal that is slower focusing than the kit lens on my Rebel XT (18-55)? I have tried it both with the IS on and off.

[robertwgross]

In general, a zoom lens with a closer focal length range will focus a little faster than a zoom lens with a broader focal length range, but there are exceptions. A fixed length lens tends to be even faster yet.

---Bob Gross---

[CyberDyneSystems]

On the other hand,. the 28-135mm has a USM focus motor does it not?
And the 18-55mm does not?

I have not used either lens much,. but my own experience with USM equipped lenses would lead me to believe the 28-135mm would focus MUCH faster than the kit lens...

[funpix]

What I am experiencing is the larger lens which has USM actually focuses slower than the small lens. Any ideas why?

[MrChad]

My 75-300 IS USM is the slowest focusing lens on Earth.

The larger zoom focal length of the 28-135 IS vs. 18-55 may be the issue.
I usually have to pre focus my 75-300 IS USM manually, but it's also not a ring type USM.

Is your 18-55mm EF S also a USM lens? Likely it won't make a difference, there is also so little mass to move on the kit lenses to get them into focus.