Quality of the IS function

[Sniper]

I don't know how long the IS lenses has been out there, but has anybody experienced that the IS function after a while has "broken down"? Or is it just lasting for ever? Does it need adjustmedt after some years? Does anybody know?

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Anders
http://www.pbase.com/sniper/

[onsouthpond]

I got a 75-300 when they first came out, not sure how long ago. They don't last forever.
I had to have it rebuilt about 18 months ago.
The rebuilding was done by Canon and cost between $100-$170.

I use it a lot for people pictures.

[50/1.4]

I got my 75-300 IS when it first came out, too. It is still working fine. I've seen somebody using a 28-135 IS and he was activating the IS every time, even when he didn't actually shoot and was metering or whatever. Avoid excessive use in this way. BTW, if you are thinking of buying one, they do consume battery power. I use mine with a Rebel X + BP-8 battery pack using NiCads.

[GenEOS]

I have had my 100-400IS for about 2 years now with no signs of break down.

[dblunt]

Hmm, guess I didn't read the manual. I leave the IS on my 28-135 on all the time unless I'm doing long exposure work. Am I seriously diminishing the lifetime of the device by doing that???

[Morden]

Hmm, guess I didn't read the manual. I leave the IS on my 28-135 on all the time unless I'm doing long exposure work. Am I seriously diminishing the lifetime of the device by doing that???
Ditto. I only disable IS on my 28-135 when using a tripod. I can live with the battery drain, but never before considered the 'life' of the IS system.

You guys have me worried!

[defordphoto]

I only use the IS on my 28-135 when it's needed.

[dblunt]

I found the manual. It only talked about turning IS off when removing from the camera (which I don't really believe if the camera is powered off) and, disabling when using a tripod or when moving in a car (which I can understand from the velocity in one direction).

I mainly leave it on just because it's another thing to have to remember to set (or unset) in what (for me) are a limited number of situations. I did note the fact that the manual says wait 1 second after depressing the shutter release half way. I haven't observed negative effects in not doing this.

$0.02

[alexz]

Well, I have relevant (unfortunate) experience.
Once swapping to Canon (I used to be Minolta user for quite a long time) I opted for a used EOS-3 that came with 28-135 IS deal I figured out for a reasonable price.
Soon after begining shooting with this lens, I stumbled upon weird and very annoying thing - over half of teh pictures I did ( several rolls) there was quite noticeable uneven sharpness across the picture field from right to left. I burnt several rolls just to sort out variables trying reveal the offender by elimination way. I borrowed friend's Rebel with just plain 28-80 and swapping teh bodies and lenses I figured out the 28-135 was the one causing the problem. Moreover, switching on and off teh IS didn't seem to make the difference.
I brought the setup to trusty Canon service lab and the setup was inspected by their chief who is the most knowledgeable and experienced Canon camera guy around. He wasn't able to figure out clearly any focusing problem checking it on culimator, however he agreed the proble is the lens, not the body.
After a few additional testings, we came to the conclusion that though IS doesn't seem to affect the performance, the issue is likely hidden in faulty IS. According to the guy's extensive experience, IS (especially the units used in consumer lenses) aren't the most reliable mechanism and tend to brake down fairly quick in many cases even with no obvious external reasons. moreover, in many cases of brake down, the IS floating element just may stack at certain angle to the film plane distorting the sharpness across the frame, while this may or may not appear on each frame.
This is the most difficult probelm to locate due to its random nature. Frankly, he wuoldnt' recommend the consumer IS lenses for one who doesn't absolutely need this feature due to very high premium you pay for non-very reliable technology. Having said that, it shoudl be realized that we are talking about general reliability, so the point is that in thsi range of lenses the failures are much more frequent events than on pro-grade gear.
The 70-200 IS for instance, is equipped with second (or even third) generation of IS that is more reliable and perhaps can be trusted much more then consumer lense equipped with IS.
Since then I sold my 28-135 for what it worth and made up my mind for giving up the IS and strecthing for the real pro performacne such as 28-70/2.8L and 70-200/2.8L, even though realizing all the benefits of IS technology.

Alex