Is my 70-200 f/4 IS working right?

<p>Hi,</p>

<p>Just bought a used 70-200 f/4 IS. I have previously used Tamron VC lens', so I am used to that type of stabilization. My concern is that the image doesn't seem to freeze up in the viewfinder. I can hear the mechanics working inside the lens, I can hear the click on, the humming, and the click off. But, the image doesn't noticeably stabilize in the viewfinder. With the tamron, there is no mistaking it, the image very quickly goes from slightly shaky to totally stable. Is the canon supposed to very noticeably stabilize in the viewfinder, or is it more subtle? Thanks for any help you can offer. </p>

<p>Matt</p>

<p>My limited experience with Tamron and Canon IS systems is that the Canon system seems to be "smoother" than the Tamron. Tamrons seem to lock in and then "jerk" when the VC system reaches its tracking limit.</p>

<p>Both seem to work equally well, but I have noticed they look a little different through the viewfinder</p>

<p>This is what I wrote last year when I reviewed the Tamron 70-300/4-5.6 VC lens (from <a href="http://www.bobatkins.com/photography/reviews/tamron_70-300_vc_review2.html">http://www.bobatkins.com/photography/reviews/tamron_70-300_vc_review2.html</a>)</p>

<blockquote>

<p>The Tamron VC seems to make the image "jump" more than the Canon IS when stabilization starts up and is sometimes seems to "jerk" the image during use more than the Canon system, but it seems just as effective once in operation.</p>

</blockquote>

<p>Are your photos blurry? I could get sharp photos at 200mm @1/30 sec with my f4IS, probably a stop better than my 70-200mm f2.8IS (I) , making the f4 a good of a low light lens (for non-action shots). I would take multiple test shots with the IS on and off, the IS should give you at least 2 stops (typ 3-4).</p>

<p>Sidenote:<br>

Bob,</p>

<p>Thanks for the great review. I've been looking at the Tamron for a travel zoom; especially for those times a 70-200mm bright white lens isn't practical, or I need more reach. I think, the L for professional work, and Tamron for travel/more reach.</p>

<p>I found a couple reviews for the Tamron, but definitely appreciate and value your opinion.</p>

<p>Ok it seems to be working, not quite as well as I imagined it would. I think I was just panicking because it is so much smoother than the tamron VC. Thanks a lot Bob, and Dave. I agree about the jerk of the tamron, that is what I am used to, it is really noticeable, so I was concerned when I didn't see a similar jerk, or lock, with the canon. But, the sharpness speaks for itself. Good call, Dave. Thanks. </p>

<p>The IS system in the 70-200 F4 LIS is very noisy - much nosier than any of my other Canon IS lenses. </p>

<p>I haven't used any non-Canon stabilized lenses, so I can't compare Canon's with others, and your model isn't one I've owned. But I've owned five Canon IS lenses over the years (28-135/3.5-5.6, 300/4L, the first generation 70-200/2.8L, 24-105/4L, 17-55/2.8; I still have the last three). What I see in the viewfinder when IS is engaged varies somewhat between lenses; the newer ones have more advanced IS versions, and of course a longer focal length provides more magnification of handheld shakiness. But for all of them, IS takes what would otherwise be somewhat jerky motion and turns it into a smooth "swimming" motion.</p>

<p>There is nothing wrong with your lens. Your images should be very sharp at f/4 at all focal lengths with IS on.</p>