A question about the 70-200 F/4.0L IS lens from Canon.
I have recently purchased this lens after reading many positive articles about it for about $1350 Canadian to use with my 30D. For the most part I am quite impressed; however, I found something that is slightly disturbing. When I shoot at higher shutter speeds, I am actually finding that the images taken with the stabilizer on are substantially less sharp than the same shot taken with the stabilizer off.
I am thinking to myself that either the lens is defective, or the stabilizer should be off at higher shutter speeds (Sp >1/100 ??). It certainly does work well at slower shutter speeds (Sp < 1/100), but at higher speeds it seems to be a gamble. I was under the impression that the stabilizer would provide a noticeably sharper image at any shutter speed. I have been experimenting with Mode 1 as I have not been panning to shoot moving objects.
Has anyone experienced this or have any advice?
Is there a rule of thumb I can use to know when to turn the stabilizer on or off? It seems a little odd to me that a fairly expensive lens with image stabilization can actually cause image blur at high shutter speeds.
What you are describing is definatly not the way IS should be working, I have seen tests that show it is beneficial up to 1/750th (progressively reducing) so if it producing worse results above 1/100th you may have a defective unit. Do you have the IS on mode I (not panning mode) this is the only problem I can image but I wouldn't expect this to produce softness in most images.
I have the 300f4 and the IS remains on all the time (except on a tripod but with the new whiz bang IS the 70-200 f4 has you don't need to worry about this).
If you are sure you've tested this thoroughly I would look at sending it back for a new one.
Jon Austin wrote:
It takes the IS mechanism a second or so after it is initially engaged, to stabilize the image. Are you giving it sufficient time to "settle down"?
This has been my experience with the 24-105 as well. I found that waiting a second before pressing the button alleviates the problem. If this is normal, I wonder how IS behaves in burst mode.
Based on the images you posted, there does appear to be a problem. Bottom line, it has to be either hardware malfunction or operator error. If you're comfortable that your technique is correct, then I'd recommend that you take the lens back to the point of purchase for an exchange (or refund), or if past the return period, send to Canon for warranty repair.
As I said, I have seen this - high ss, with and without IS, I thought the IS off pics were sharper. But this was only with pixel peeping and it wasnt really prominant.Notihng like in your pics.
You took this picture by half-pressing, waiting a second without panning around at all, then shooting, right?
If so, you've got a problem. That's a pretty dramatic reduction in sharpness. I've never seen anything like that with my 28-135IS or 100-400IS (both of which have much older variants of IS, which should be LESS effective).
If you can't exchange the lens for another copy, I'd send it in to service.
Unless I missed detecting the blurry images of mine, I don't think that is my experience. I practically have never turned off the IS of my lenses and I use quite a few IS lenses regularly, ranging from 28-135IS to 500f4IS, at all kind of shutter speed. If you have already allowed the IS a chance to stablize, I hate to say that what you are experiencing is not normal. Although I am still waiting to get my 70-200f4IS, its IS system cannot be that much different from others.
