Canon EF 70-300mm f/4.5-5.6 DO IS USM

Regarding the Canon EF 70-300mm f/4.5-5.6 DO IS USM lens, am I correct that
the front does not rotate or extend-retract with focus and zoom? This
information is not apparent to me from Canon's specifications and chart. A
non-rotating and non-extending design is critical for certain
instrumentation applications.

 

Take a look here:
http://www.the-digital-picture.com/Reviews/Canon-EF-70-300mm-f-4.5-5.6-DO-IS-USM-Lens-Review.aspx
http://www.dpreview.com/news/0401/04012902canon70300do.asp

It does extend/retract. 70-200 doesn't.

 

That lens is one of the very few that have a lock to prevent "lens
creep"; if you hold it with the front element toward the center of the
Earth, and the lock is not engaged, the lens lengthens considerably.
Seems to me this indicates it is not non-extending.

Nice piece of kit, otherwise.

 

I just bought this lens, good thing I read the instructions about the
lock.

I have only had it for day and only a few minutes to play. Has anyone
found the IS "motor" to be noisy as in a whirring sound. I have the
17-85mm IS and I don't hear anything so any sound caught me off guard. I
called the store and the salesperson claimed that was normal. Not that
I distrust that person but I will take it to the store for an up close
listen.

In the mean time can anyone with the same lens shed some light on the IS
noise? If it makes a difference it's mounted on an XTi.

-Doug

 

I shot with this lens for about a year or so. I found it an excellent travel
and hiking lens for wildlife.

What I noticed many times is that it is sharp between 70 and 200 but gets
progressively softer going out toward 300mm.

I've since sold this and bought the 100-400 IS.

Steve
Tucson AZ

 

Handheld, tripod, or both?

And how did the 100-400n behave 200+? Was the 100-400 worth twice the
cost?

And my original question was the IS motor noisy?

-Doug

 

So far, my observations with the 100-400 is that it's quite sharp out past
300.

As for cost, I paid $1000 for the DO and about $1250 for the 100-400. (Both
used on eBay.)

 

You can definitely hear the IS motor, as for the lens, I had one and did not
find it to be very sharp, and not just at the long end, so I traded it in
for a 300mm f4 IS L which is great. If I remember right, the focus motor
was very quiet.

Jean

 

Thank you!!!

-Doug (the nicer one)