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Photo Forum / Digital Photography / DSLR Cameras / December 2006How do I know if an IS lens is working?
Bit of an odd question here, but... I bought a Canon 75-300 IS lens some time ago. It's the only IS lens I own, and the only one I've ever used. When I got it, the first thing I did, naturally, was take some test shots with and without IS to see how much difference the stabilization made. The results were kind of inconclusive; in some shots, the IS seemed to make a big difference; in others, I couldn't tell the difference between the pictures with and without the stabilizer turned on. Then, a few weeks ago, I was using the lens, and was surprised by an odd noise the lens was making. When I held down the shutter button, there was a sort of whirring, mechanical noise from inside the lens. It did this for a few shots, and I haven't heard it since. But it got me wondering. I'd never thought about it before, but I'd expect the IS mechanism to make that sort of sound. However, my lens is completely silent (except from the focusing mechanism, which is Micro USM). So now, I'm a little concerned that the IS feature that I paid for may not actually be working. I feel a little foolish wondering about this after having owned the lens for over a year, but...does the IS mechanism normally make noise? Is there some way for me to definitively confirm that the stabilizer is actually working? Thanks, - Darryl > Bit of an odd question here, but... > [quoted text clipped - 10 lines] > there was a sort of whirring, mechanical noise from inside the lens. It > did this for a few shots, and I haven't heard it since. Well I have Nikon VR but yes it makes a whirring sound when you tap the shutter, then turns off in a few seconds. Since we're not afraid of dumb questions, is it possible the on/of switch for the IS got switched? :-) Or maybe the contacts are dirty. > But it got me > wondering. I'd never thought about it before, but I'd expect the IS [quoted text clipped - 9 lines] > Thanks, > - Darryl > Well I have Nikon VR but yes it makes a whirring sound when you tap the > shutter, then turns off in a few seconds. Since we're not afraid of dumb > questions, is it possible the on/of switch for the IS got switched? :-) > Or maybe the contacts are dirty. Yes, I checked the switch (tried it in both positions). In fact, what originally happened was: I had the camera on a tripod, with the IS turned off (since I've been told that the IS on that lens can actually be detrimental with the camera on a tripod). When I took the camera off the tripod, I switched the IS back on. That's when I noticed the noise. I thought "Hey, I've never heard that before...is that the IS?" I looked through the viewfinder, and it seemed to me that I was actually -seeing- the IS work, for the first time. To confirm, I switched the IS back off. The noise etc. went away...when I switched it back on again, there was no change. As far as I can remember, that one occasion is the only time I've heard the lens make any noise, and it's also the only time I can remember seeing any effect in the viewfinder. It hasn't done it since. I checked the contacts of both lens and camera, and they're clean. The one thing I do want to do yet is try the lens on a different body (I don't own one, but I know a couple people who do) and see what happens. Thanks for the suggestions, - Darryl Hi, > I thought "Hey, I've never heard that before...is that the IS?" I > looked through the viewfinder, and it seemed to me that I was actually > -seeing- the IS work, for the first time. To confirm, I switched the IS > back off. The noise etc. went away...when I switched it back on again, > there was no change. I don't have an IS lens but one of my clients has a 70-300mm Canon IS lens and I've tried it on my camera (Rebel XT). If you hand hold it and look through it at 300mm without the IS and then turn the IS on, you will see _immediate_ and noticable change. With IS the image in the viewfinder sort of "floats" where as without IS the image in the viewfinder will shake or vibrate. I didn't notice if it made any sounds with the IS on, but I would expect some kind of noise when the mechanism operates. Best regards, Arnor Baldvinsson San Antonio, Texas > Bit of an odd question here, but... > [quoted text clipped - 19 lines] > mechanism normally make noise? Is there some way for me to definitively > confirm that the stabilizer is actually working? The IS normally makes a little noise. Typically there is also a (more noticeable) click when it starts and stops. A quick check is quite simple. First, make sure the IS switch on the side of the lens is set to "on" or "mode 1". Then look through the viewfinder, half-press the shutter button, and shake the camera slightly. The image in the viewfinder should move slowly and lag behind your shaking a bit. Do it again with IS switched off. You should see the viewfinder image shake much more, and with no lag. If you can't tell a significant difference with IS on or off, something is wrong.  SignatureMåns Rullgård mru@inprovide.com > The IS normally makes a little noise. Typically there is also a (more > noticeable) click when it starts and stops. A quick check is quite [quoted text clipped - 5 lines] > shake much more, and with no lag. If you can't tell a significant > difference with IS on or off, something is wrong. There's no click or other noise (though that's a pretty good description of what it did the one time). Nor is there any difference in the viewfinder that I can discern. I've cleaned the contacts on both the lens and the camera, to no avail. I've also checked my warranty, and, naturally, I'm outside the warranty period. Which annoys me, because if the IS isn't working now, then it hasn't worked since the day I bought the lens, and I simply didn't realize it. Chalk one up to inexperience, I guess :-( - Darryl Nor is there any difference in the viewfinder that I can discern. Did you try it at full zoom? You should see a difference. If you paid with a credit card you may have doubled the warranty, check your terms and conditions. I pay all my high tech stuff with my credit card and a couple of times it was worth it, once I had a Canon S400 which needed work past the one year of warranty so I brought it in had an estimate drawn up, sent it to the insurance company my credit card had made arrang,ments with and they paid the bill ($250). Jean Måns Rullgård wrote: > The IS normally makes a little noise. Typically there is also a (more > noticeable) click when it starts and stops. A quick check is quite [quoted text clipped - 5 lines] > shake much more, and with no lag. If you can't tell a significant > difference with IS on or off, something is wrong. There's no click or other noise (though that's a pretty good description of what it did the one time). Nor is there any difference in the viewfinder that I can discern. I've cleaned the contacts on both the lens and the camera, to no avail. I've also checked my warranty, and, naturally, I'm outside the warranty period. Which annoys me, because if the IS isn't working now, then it hasn't worked since the day I bought the lens, and I simply didn't realize it. Chalk one up to inexperience, I guess :-( - Darryl > If you paid with a credit card you may have doubled the warranty, check your > terms and conditions. I pay all my high tech stuff with my credit card and > a couple of times it was worth it, once I had a Canon S400 which needed work > past the one year of warranty so I brought it in had an estimate drawn up, > sent it to the insurance company my credit card had made arrang,ments with > and they paid the bill ($250). Hey, I didn't even think of that. I just checked the terms of the credit card I used, and it claims "doubles the warranty, up to one additional year". That should cover me. I'll have to take the lens down to my local shop (so that they can confirm that there's actually a problem with it, for one thing), and then give my credit card company a call. Thanks! - Darryl There is a service notice on that particular model lens concerning the IS system. If the third digit of the serial number is "0" or "1", the lens may have the covered problem and can be sent to Canon for a no-cost inspection and repair. Details are here... http://www.usa.canon.com/consumer/controller?act=PgComSmModDisplayAct&keycode=21 12&fcategoryid=216&modelid=11922 It only took about 2 weeks for mine to get returned to me after sending it to them. If you don't like clicking on links in newsgroup messages, you can get to the service notice from the Canon webpage for this model lens by clicking "Support" then "Support & Service". >There is a service notice on that particular model lens concerning the IS >system. If the third digit of the serial number is "0" or "1", the lens may [quoted text clipped - 9 lines] >the service notice from the Canon webpage for this model lens by clicking >"Support" then "Support & Service". Yes you get essentially a new lens. They replace everything except the outside case. SignatureScott in Florida >There is a service notice on that particular model lens concerning the IS >system. If the third digit of the serial number is "0" or "1", the lens may [quoted text clipped - 9 lines] >the service notice from the Canon webpage for this model lens by clicking >"Support" then "Support & Service". That's a different lens than the one the OP say he has. Jack Mac > Bit of an odd question here, but... > [quoted text clipped - 22 lines] > Thanks, > - Darryl I would find a 70+ year old friend, and....Wait! I am 71, so I would do) have him take some hand held shots at around 1/50 of a second of anything stationery, like a house. Then take the same picture myself from a tripod, blow them up, and compare the two....The IS/VR photo should be almost as sharp as the one taken from the tripod, if the VR is working...... "William Graham" <weg9@comcast.net> wrote: > I would find a 70+ year old friend, and....Wait! I am 71, so I > would do) have him take some hand held shots at around 1/50 of a > second of anything stationery, like a house. Then take the same > picture myself from a tripod, blow them up, and compare the > two....The IS/VR photo should be almost as sharp as the one > taken from the tripod, if the VR is working...... No need to take any photos to tell if IS is working. When handholding the camera at 300mm with IS turned on, there should be an immediate and noticeable steadying of the image in the viewfinder when the shutter release is partially depressed. As mentioned by several other people in this thread, the difference will be immediate and very obvious in the viewfinder at 300mm. If no difference is seen, something is wrong. >> I would find a 70+ year old friend, and....Wait! I am 71, so I >> would do) have him take some hand held shots at around 1/50 of a [quoted text clipped - 10 lines] > and very obvious in the viewfinder at 300mm. If no difference is > seen, something is wrong. Yes. It's interesting to note, that I wondered why the VR lenses didn't make any noise, because I couldn't understand how they could work without some kind of gyroscope action going on....Upon reading this thread, I have found out that they do make a noise, and so they do have that action going on.....:^) > Yes. It's interesting to note, that I wondered why the VR lenses > didn't make any noise, because I couldn't understand how they > could work without some kind of gyroscope action going on....Upon > reading this thread, I have found out that they do make a noise, > and so they do have that action going on.....:^) As I understand it, no gyroscopes are involved. Stablized lenses use accelerometers to measure the movement of the lens body, then move an internal element in the opposite direction (more or less), so as to cancel the detected movement. SignatureRay (remove the Xs to reply) >> Yes. It's interesting to note, that I wondered why the VR lenses >> didn't make any noise, because I couldn't understand how they [quoted text clipped - 6 lines] > internal element in the opposite direction (more or less), so as to > cancel the detected movement. Hmmm, that sounds tricky. Gyroscopes seem sensible because they are sensitive to rotational (not translational) motion, and that is what is going (generally) to blur your photo asa a result of shake. Whereas to do the same thing with accelerometers would mean differentially sensing opposite sides of the body to detect rotation. D'you follow my logic? Mike. SignatureIf reply address = connectfee, add an r because it is free not fee. >> As I understand it, no gyroscopes are involved. Stablized lenses >> use accelerometers to measure the movement of the lens body, then [quoted text clipped - 7 lines] > differentially sensing opposite sides of the body to detect > rotation. D'you follow my logic? Here's Canon's explanation: http://www.canon.com/camera-museum/tech/room/f_index.html It mentions a "gyro sensor", without explaining what it means. But the actual image stabilization is done by moving a lens element. It occurs to me that I may have misunderstood your reference to gyroscopes. Did you mean using the gyroscopic effect to keep the lens from wobbling, or just using a gyro as a rotation sensor? I assumed you meant the former, but if you meant the latter, then "never mind", as Emily Litella would say. SignatureRay (remove the Xs to reply) >>> As I understand it, no gyroscopes are involved. Stablized lenses >>> use accelerometers to measure the movement of the lens body, then [quoted text clipped - 16 lines] >gyroscopes. Did you mean using the gyroscopic effect to keep the lens >from wobbling, or just using a gyro as a rotation sensor? The "gyro" senses the movement, electronics then amplify this and drive a coil on which the lens element is mounted to correct for the movement. There is a vast amount of discussion about whether these are "gyro"s in the true sense or not - they aren't, they are technically accelerometers. I work for the company which invented the "gyro" that is used and it is manufactured under license by Sumitomo and others. It is a small mass of silicon suspended on silicon strain gauges, all mounted in a compact package no larger than a TO5 transistor can (although several packages are produced). All of the patent and other literature I have seen within the company refer to it as a "silicon gyro" - but that could be because we make lots of other gyro systems, including good old mechanical types and ring laser gyros. It is deployed in many applications. Five of these same devices are used in each of the Segway "wheeled pogo-sticks" to keep them from falling over with anyone but an idiot in control, as GWB demonstrated a couple of years ago. http://news.bbc.co.uk/1/hi/world/americas/2989000.stm http://politicalhumor.about.com/library/images/blbushsegway.htm My colleagues claim he inadvertently switched it off... SignatureKennedy Yes, Socrates himself is particularly missed; A lovely little thinker, but a bugger when he's pissed. Python Philosophers (replace 'nospam' with 'kennedym' when replying) > The "gyro" senses the movement, electronics then amplify this and > drive a coil on which the lens element is mounted to correct for [quoted text clipped - 9 lines] > mounted in a compact package no larger than a TO5 transistor can > (although several packages are produced). [snip] Does a single sensor do multiple axes? I remember reading about these, but don't recall details. I would guess it would be possible to get two axes out of one device, which (I think) should be enough for IS. SignatureRay (remove the Xs to reply) >> The "gyro" senses the movement, electronics then amplify this and >> drive a coil on which the lens element is mounted to correct for [quoted text clipped - 14 lines] >but don't recall details. I would guess it would be possible to get >two axes out of one device, which (I think) should be enough for IS. There are one and two axis versions - I don't know which is used in the IS systems. Probably different for different manufacturer designs. SignatureKennedy Yes, Socrates himself is particularly missed; A lovely little thinker, but a bugger when he's pissed. Python Philosophers (replace 'nospam' with 'kennedym' when replying) > I work for the company which invented the "gyro" that is used and it is > manufactured under license by Sumitomo and others. It is a small mass > of silicon suspended on silicon strain gauges, all mounted in a compact > package no larger than a TO5 transistor can (although several packages > are produced). Do they make any sound in operation? My 70-200 IS lens goes CLACK (probably releasing the correction element) whrrrrrrrr (constant, sorta toneless, mechanical "spinning things" sound, even with the lens standing on the floor, i.e. the lens looks downward and no lateral movement nor acceleration. Gyros?) tir-ir-ir-p or t-or-or-or-or-p (when turning camera+lens up/down or left/right. Sounds a bit like a stepper engine in an old floppy drive. The correction element moving back because it physically cannot correct that far a move?) Of course, the sound is very hushed, you wouldn't hear it 2 steps away, except maybe for the start CLACK. -Wolfgang [IS stabilising] > It occurs to me that I may have misunderstood your reference to > gyroscopes. Did you mean using the gyroscopic effect to keep the lens > from wobbling, or just using a gyro as a rotation sensor? I assumed > you meant the former, but if you meant the latter, then "never mind", > as Emily Litella would say. The latter. Though you can get the former, e.g. here: http://www.ken-lab.com/stabilizers.html I doubt they fit *into* the typical lens, though. -Wolfgang > [IS stabilising] > [quoted text clipped - 3 lines] >> assumed you meant the former, but if you meant the latter, then >> "never mind", as Emily Litella would say. I didn't actually write that, though I know that someone else did. And furthermore I have no idea who Emily Litella is, or was, or what she might say! And in any case the precession that gyroscopes get into when there is any attempt to move them (or resist their free movement which is the same thing) would make them unsuitable for direct use in that way, quite apart from the weight that they would have to have to be effective. I must look up, sometime, how small and cheap laser gyroscopes can be made these days... Mike. SignatureIf reply address = connectfee, add an r because it is free not fee. > Here's Canon's explanation: > http://www.canon.com/camera-museum/tech/room/f_index.html > It mentions a "gyro sensor", without explaining what it means. But > the actual image stabilization is done by moving a lens element. I still haven't looked up that reference. But there is a type of "gyro" that I don't think has been mentioned in this thread. It is more like a Foucault's pendulum (he apparently invented the gyro too) than either original rotating gyros or the "rotating" laser light version. It uses a vibrating mass to sense movement and you can buy your own from http://gyroscope.com/d.asp?product=PIEZO for less than 100 dollars (single axis). Mike. SignatureIf reply address = connectfee, add an r because it is free not fee. > Yes. It's interesting to note, that I wondered why the VR lenses didn't make > any noise, because I couldn't understand how they could work without some > kind of gyroscope action going on... There are non-mechanical gyroscopes. Since bearings only last so many thousand hours, satellites tend to prefer these solutions: http://en.wikipedia.org/wiki/Fibre_optic_gyroscope ff. These are not used for IS, though, as far as I know. -Wolfgang >> Yes. It's interesting to note, that I wondered why the VR lenses didn't >> make [quoted text clipped - 10 lines] > > -Wolfgang I had not heard of this device....I am still trying to figure out why the two beams of light will arrive out of phase when the loop is rotated. Is this dependent on the momentum the photons feel as they travel through the coil? - In any case, it certainly beats the flywheel method, as it is completely non-mechanical and 100% electronic..... [fibre optic gryos] >I had not heard of this device....I am still trying to figure out why the >two beams of light will arrive out of phase when the loop is rotated. Two beams of light are sent round the ring simultaneously. If the ring is stationary they both reach the start point again at the same time. If the ring rotates then one beam will reach the start point again earlier than the other. The phase difference between the two beams gives the angular velocity. Plenty of maths explaining it linked from the wikipedia article if you're into that sort of thing. Rather neat. Frink SignatureDoctor J. Frink : 'Rampant Ribald Ringtail' See his mind here : http://www.cmp.liv.ac.uk/frink/ Annoy his mind here : pjf at cmp dot liv dot ack dot ook "No sir, I didn't like it!" - Mr Horse >[fibre optic gryos] > [quoted text clipped - 6 lines] >earlier than the other. The phase difference between the two beams >gives the angular velocity. And they make really nice thermometers too. ;-) SignatureKennedy Yes, Socrates himself is particularly missed; A lovely little thinker, but a bugger when he's pissed. Python Philosophers (replace 'nospam' with 'kennedym' when replying) > Two beams of light are sent round the ring simultaneously. If the ring > is stationary they both reach the start point again at the same time. > If the ring rotates then one beam will reach the start point again > earlier than the other. The beams reach the start point at the same time, it is just that the 'start point' emitter/detector has moved since the light was emitted and so the phase difference indicates the rate of rotation. To increase sensitivity many, many loops of optical fibre are used and the beam travels 1,000 times around the loop before being recombined with the emitter beam and detected. The intensity of the recombined beams differs with phase difference in the two beams. If the emitter is stationary and only the detector moves [actually, a mirror moves and the detector is stationary with the emitter - but you get the gist] then the phase difference indicates the absolute displacement and the frequency shift indicates the velocity. The technology for doing this is late 1800's: http://en.wikipedia.org/wiki/Michelson-Morley_experiment SignatureNicholas O. Lindan, Cleveland, Ohio Darkroom Automation: F-Stop Timers, Enlarging Meters http://www.nolindan.com/da/index.htm n o lindan at ix dot netcom dot com > > I would find a 70+ year old friend, and....Wait! I am 71, so I > > would do) have him take some hand held shots at around 1/50 of a [quoted text clipped - 10 lines] > and very obvious in the viewfinder at 300mm. If no difference is > seen, something is wrong. By way of followup: I took the lens down to my local Canon service centre (luckily, there is one in the city...the next nearest is two provinces away), and the technician was initially pessimistic, expecting that the entire IS mechanism was faulty and needed replacing. However, it turned out that the switch needed repair, and I've got the lens back now (two days later!). The repair job was $50 (labour only; no parts) and should be covered by my credit card's warranty extension. The difference is -extremely- noticable, both in the viewfinder and in the images themselves. I'm actually somewhat astonished at the magnitude of the difference; my first test shot was 1/30 sec at 75mm, and, while not pin-sharp, it's quite good (the same shot without IS was complete trash). Thanks to all who responded! - Darryl |
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