70-200 2.8L IS - Noisy IS?

[paulhillion]

When I focus I can hear the IS making a whirring sound which lasts for a couple of seconds or the entire time I'm in AI Servo mode and have the focus button depressed. It seems quite loud or maybe I've just not noticed it before until today when I used it in a quite room. My 100-400 IS does make a noise but it doesn't appear to be as noisy? The lens appears to be working fine so is this 'noise' just normal?

Thanks for hopefully putting my mind at rest!

[Longwatcher]

Mine seems to be getting louder as well (or my hearing is getting better). It used t be quieter then my 100-400, but lately it is noiser. Almost as loud as I remember my 75-300 IS being last time I used it.

It may just be age or maybe it is starting to wear.

I notice hard drives occasionally get louder for awhile and then quiet down. If they keep getting louder, then I start expecting failure and plan on replacement soon. So I supoose I see the Gyro in the IS as doing the same thing as most high-speed spinning objects, getting cranky in their mid-life and then settling down for a long awhile.

If it ever gets above a certain noise level then off to Canon it will go, if it hasn't died already.

[pcasciola]

Maybe you have better hearing than me, but I don't notice any noise from my 70-200/2.8L IS. My 300/4L IS does make all kinds of strange noises though, and does seem to compensate for more shake than the 70-200/2.8L IS, but I definitely find the IS on the 70-200 to be much smoother in operation and much quieter than the IS on the 300/4L.

[condyk]

My ex Canon 28-135 IS certainly had an IS related noise. As it was new December 2004 and had little use I assume it was perfectly normal. Was faint and worked very well so I only thought about it reading this thread ... maybe there's a lesson there!?

[paulhillion]

Well it's certainly not 'age' as my lens is only a few weeks old. It's noticably louder than my 100-400 and of course when I heard it this morning I thought it had developed a fault. However all seems to be working ok.

[pierrot]

Hmm, it's your fault Paul: don't walk about the hazy shores of your lost island, everything will turn to rust around there... :mrgreen:

[paulhillion]

OK so I just want to double check with you 70-200 2.8LIS owners - when I press the shutter down to focus the IS (motor, whatever it's called) can be heard to start up and lasts for approx 2 seconds even after the focus 'beep' has sounded. Is this normal? I guess you'd have to do this in a quiet room :-)

Thanks.

[paulhillion]

Should have done this first but I hear that the IS on my 100-400 acts pretty much the same although a little quieter and with an added faint beep?? I guess I'll have to get used to these IS noises!

Whilst on the subject is there a difference in versions between the 100-400 IS and the 70-200 IS? It's just that with the 100-400 I notice the IS sort of 'snaps' into place where as the 70-200 IS seems a great deal smoother?

Thanks for letting me natter away (to myself probably :))

[pierrot]

Yes of course, the gyros have to spin to keep the IS working. They'll do that each time you keep the shutter half depressed, then stop after approx. 2 secs to avoid draining the battery too quickly.

Thus, you're supposed to shoot within these 2 secs after depressing the shutter halfway. If not, the gyro motors will stop (and start again next time you'll frame/focus a new view).

[lancea]

Are there really motorised gyros in the Canon IS lenses? I had a hunt around the web after a recent posting, and came away with the impression that they use microaccelerometers. Tiny little devices that seem to be more like vibration/movement sensors than gyros.

[tim]

My IS mechanism is quieter than the lens focusing, or maybe about the same volume.

[Longwatcher]

Are there really motorised gyros in the Canon IS lenses? I had a hunt around the web after a recent posting, and came away with the impression that they use microaccelerometers. Tiny little devices that seem to be more like vibration/movement sensors than gyros.

Canon says they use a Gyro. I tend to trust the people who built it to be the most accurate.

http://www.canon.com/camera-museum/tech/room/f_index.html
The vibration detecting gyro sensor detects the level of camera shake and the actuator moves a part of the optical system (IS lens group) vertically to the optical axis depending on the degree of camera shake, to stabilize the image on the film plane.


I highly recommend the Canon Camera-Museum site.

[lancea]

Canon says they use a Gyro. I tend to trust the people who built it to be the most accurate.
With respect, that site gives only the very briefest of mentions. That was the link that first got me interested. I am interested in the technology, and can find only extremely limited and ambiguous information about Canon IS. Microaccelerometers can be referred to as "gyros", but I don't know if they are gyros in the sense that the word "gyro" is being used in this thread - as spinning discs that might be the source of the noise. For instance, do a Google search on "piezoresistive microaccelerometers". I haven't given a specific link because these papers were just a bit too technical for me :)

I've also searched the newsgroups, and while I can find lots of posts that say Canon is using spinning disc gyros (and that you can hear them), there's also plenty that say they use solid state devices and that the noise is the "correction" motors. One comment made several times is that only Canon seems to know for sure what they use. Not too surprising for a patented system.

Does anyone have a reference to the patent, or have a link to something that gives a definitive technical explanation?

[flapsmcgee]

My IS mechanism is quieter than the lens focusing, or maybe about the same volume.

Haveing recently bought the 70-200 2.8 is id have to agree......

awesome lens very quiet and pin sharp

[Longwatcher]

Based on what I read in a couple of papers and given the date at which Canon started using image stabiliazation.

Canon is using micromachined gyro stabilization systems.

Microaccelerometers did not have the ability to respond to the multi-directional small changes required to perform image stabilization at the time Canon started implementing it with the 75-300 IS in Sept 1995.

I did learn though that what I had thought of as a gyro was not completely correct (I always think of a spinning top). In reality Canon probably uses a pair of vibrating ring-gyros although apparently in 1998 technology had some early vibratory gyros that did not have any rotating parts, it just measured the amount of vibration in various spokes of the device providing a similiar result. A vibratory ring gyro apparently

Given the .5 to 1 second start up time this is also consistant with a ring-type gyro if I understand it correctly. The accelerometers and pure vibration gyros don't require any (or as much) start up time. I suspect that the on-sensor IS of Minolta? are accelerometer type devices.

Finally on EF75-300mm f/4-5.6 IS USM page
http://www.canon.com/camera-museum/camera/lens/f_lens.html
Level of camera shake is detected by vibration detecting gyro sensors.

So I can confirm it is a Gyro
I can confirm it is a form of vibration gyro
I think it is a ring vibration gyro.

Best research I can do in the time I had.

[DocFrankenstein]

The vibration detecting gyro sensor detects...
Well, it's not a technical explanation. They may be using term "gyro" as a "device" for all we know.

And gyros don't detect vibration...

I remember the guy who disassembled the 70-200 IS mentioned that there are no actual gyros.

[Longwatcher]

Apparently a gyro does not have to have any MOVING parts. It appears to be the principle of how the mechanism detects the movement that determines if it is a gyro or not.

An accelerometer uses a straight line movement and detects how much change there is in the object/field/conductivity over a period of time as well as intensity. You need three accelerometers to do 360 degree spherical movement correction. One for each axis

A gyro detects the direction of movement and speed of that change. You only need two gyros to do 360 degree spherical movement correction. one for X/Y and one for Z (which will also do either X or Y as well).

For both the more the better though.
The part for the 70-200 IS lens that is required has only two compartments to it, not three (although this is not necessarily an indicator as you may only need X/Y to do IS with a lens).

I could not find anything more definative that stated that Canon used a particular Gyro, If I could read Japanese or was a member of IEEE I might have been able to get access to the appropriate technical white papers.

I highly reccomend this page for the pictures
http://users.ece.gatech.edu/~ayazi/pub/Inertial_IEEE.pdf
figures 13-16 are my favorite.

I did some more research and although I still think it is a ring-vibration gyro, I could be wrong.

[lancea]

Thanks for the further info. Excellent paper. Fascinating stuff (the photos are very good)! If someone has a really unfortunate accident with an IS lens perhaps they can do a full dissection and get whatever they find under a microscope. That's probably the only way we'll ever find out the details of what Canon is using :)

[pcasciola]

Detailed photos of all the 70-200/2.8L IS parts can be found here. This guy took apart and is in the process of fixing his broken 70-200/2.8L IS:

http://home.fuse.net/pets/EOS/70-200/70-200.htm

[GyRob]

Thus, you're supposed to shoot within these 2 secs after depressing the shutter halfway. If not, the gyro motors will stop (and start again next time you'll frame/focus a new view).
__________________
Does this mean that if im paning with the camera set on A1Servo for longer than 2secs the IS has stopped working and the lens is working like a NON IS lens ?
thanks
Rob

[lancea]

Detailed photos of all the 70-200/2.8L IS parts can be found here.
Goodness. If only he could be encouraged to take to some of the bits with a diamond saw or a hammer :) Thanks for that link.

[Jon]

My 100-400 IS was inaudible when I got it. In March, I was able to hear it kick in, and the camera started locking/freezing/Err99/Err01ing me. Happened on 2 cameras, too. I sent the lens back and Canon replaced the IS. It's now much quieter again. So if you can hear the IS in an L IS USM, it may be on the brink of dying.

[paulhillion]

So if you can hear the IS in an L IS USM, it may be on the brink of dying.Hmmm I'm not so sure? I think I suddenly became aware of the IS 'noise' as I started to use it one morning a few days a go in a room that happened to be very quiet, it's not something I'd notice in everyday surroundings with your normal background noise. Having said that I've tested the lens with the IS on & off and it's plain to see the IS is working fine. I was slightly tempted to send it in to a Canon service centre but my gut feeling is that it'd come back exactly the same?

[Jon]

It "may" be on the brink . . .
I doubt that if it hasn't actually failed they'd be able to diagnose it, but if you start hearing it in normal use, I'd suggest you be wary.

[BlueTit]

Just like PCasciola I find the 70-200 fairly silent compared to the 300 f4, but neither could be described as loud even in a quiet room.

That guy doing home repairs on his 70-200 has some guts. If he manages the repair I wonder will he get it all back together!