IS On or Off & More On Image Stabilization

A cut and paste from yesterday's blog post here.

IS On or Off?

Despite the fact that the requested information is on Page 2 of The Art of Bird Photography II, I often receive e-mails that go something like this: “I heard on line that you should turn IS off when you are working on a tripod with a big lens. Is that true?”

Here, adapted from what I wrote on page 2 of ABP II, is what I have to say on the matter:

The current super-telephoto lenses lenses (the 300 & 400 f/2.8L IS and the 500 & 600 f/4L IS) feature a tripod-sensing IS system that eliminates the vibration
caused by both equipment shake and by mirror slap. Despite contradictory statements both on line and in many editions of the lens instructions, the IS switch on these lenses should be set at the “On” position at ll times, even when the lens is mounted on a tripod. (The same will be true when the Series II lenses are released.)

The next e-mail usually says, “OK. I believe you. I will keep IS on with my big lens on a tripod. Should I be in IS Mode 1 or IS Mode 2?”

To this I again reply with info adapted from Page 2 of ABP II.

With the four current super-telephotos it is best to set IS Mode 2 for all applications. Why? Because with these lenses IS Mode 2 performs exactly the same as IS Mode 1 when the lens is mounted on a tripod.

With all of the intermediate telephoto IS lenses (including but not limited to all of the 70-200mm IS lenses, the 300 f/4, and the 100-400mm) it is advised by the manufacturer (and just about everyone else) that IS be turned off when using lenses in this class on a tripod. When I do use these lenses on a tripod, I always leave IS on (set to Mode 2). Why do I disregard the manufacturer’s advise? In all the years I have been working with intermediate telephoto lenses with IS Mode 2 on, I have had only a single frame (film actually) that was affected by the IS system. The lens elements shifted during the exposure. The result was a very pleasingly blurred image. Having to remember to turn IS off and then on again while hand holding is far too great a price to pay for me. I believe that simpler is better.

More On Image Stabilization

Whether on a tripod or hand holding, Image Stabilization will help photographers using sloppy sharpness techniques to make sharper images but those photographers employing excellent sharpness techniques will be able to push the envelope much further than their sloppy, careless counterparts. (See Advanced Sharpness Techniques in Chapter VI of ABP II.

Item last. When working with the intermediate telephoto lenses and zoom lenses like those mentioned above it is recommended that IS Mode 1 should be set when photographing static subjects and that IS Mode 2 be set when panning with moving subjects. I sometimes remember to do this when hand holding but for the most part I simply set IS Mode2 and let it fly (as in the featured image here).

Nikon folks are invited to let us know how they utilize VR.

Interesting Artie,
When I was in Florida we had a discussion about this with Jim and Doug, although I don't use a tripod for bird photography I have noticed that none of the Canon lenses I have used, that is 24-105, 500 f/4, 300 f/2.8 or 300f/4 actually turns IS off when on tripod. The IS mechanism is active and you can hear the acoustic jitters.

If you put your camera on tripod and set your camera to LV you will see the image "float" on the rear LCD if IS is ON. When I do MA or sharpness test on tripod I always set IS to OFF because I have seen many times that it blurs the images, Doug can confirm this too.

After our discussions we called CPS 800 number and the person on the phone mentioned that he was not aware of any tripod-detection mechanism and recommended IS set to OFF. We also searched the lense's manuals and did not find anything indicating this feature.

Can you confirm if you have seen a Canon document that recommends IS ON on tripod?

When shooting hand hold I always use IS (and VR with Nikon).

Arash,

re:

]Interesting Artie. When I was in Florida we had a discussion about this with Jim and Doug, although I don't use a tripod for bird photography I have noticed that none of the Canon lenses I have used, that is 24-105, 500 f/4, 300 f/2.8 or 300f/4 actually turns IS off when on tripod.

I am confused as to what you mean.... A lens does not turn IS off, the photographer turns IS off by moving the switch. Please explain. Thanks.

The IS mechanism is active and you can hear the acoustic jitters.

Are you saying that when IS is turned off that you still hear it acting as if it is on?

If you put your camera on tripod and set your camera to LV you will see the image "float" on the rear LCD if IS is ON. When I do MA or sharpness test on tripod I always set IS to OFF because I have seen many times that it blurs the images, Doug can confirm this too.

I am not sure on that.... If IS makes images soft, the why are we using it? My experience is that IS improves sharpness. We do recommend that you give the image a moment to settle before depressing the shutter button while doing an alignment.

After our discussions we called CPS 800 number and the person on the phone mentioned that he was not aware of any tripod-detection mechanism and recommended IS set to OFF. We also searched the lens manuals and did not find anything indicating this feature.

I am not saying that IS will turn off when the lens is on a tripod. I am saying that the IS system will sense that the lens is on a tripod and perform differently.

Can you confirm if you have seen a Canon document that recommends IS ON on tripod?

No. I am 99.99% sure that I got that info directly from Chuck Westfall. I will write him and let you know what I learn.

When shooting hand hold I always use IS (and VR with Nikon).

Do you change from Mode 1 to Mode 2 as recommended with Canon?

Artie,

Looks like I did explain well, what I meant was that in my experience the IS system did not seem to perform correctly when on tripod and delivered soft images, I can post some examples later.

I have not seen Canon advertise this feature in their manuals, white papers or other publications, in fact as I mentioned CPS recommended IS be set to OFF on tripod. That's why I asked.

I agree IS improves sharpness when handheld, it also helps with keeping the bird centered while tracking. I always use mode 2.

Please let us know if he can provide point us to a Canon document that explains how this feature is supposed to work.

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Originally Posted by arash_hazeghi

Interesting Artie,
When I was in Florida we had a discussion about this with Jim and Doug, although I don't use a tripod for bird photography I have noticed that none of the Canon lenses I have used, that is 24-105, 500 f/4, 300 f/2.8 or 300f/4 actually turns IS off when on tripod. The IS mechanism is active and you can hear the acoustic jitters.

If you put your camera on tripod and set your camera to LV you will see the image "float" on the rear LCD if IS is ON. When I do MA or sharpness test on tripod I always set IS to OFF because I have seen many times that it blurs the images, Doug can confirm this too.

After our discussions we called CPS 800 number and the person on the phone mentioned that he was not aware of any tripod-detection mechanism and recommended IS set to OFF. We also searched the lense's manuals and did not find anything indicating this feature.

Can you confirm if you have seen a Canon document that recommends IS ON on tripod?

When shooting hand hold I always use IS (and VR with Nikon).

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Arash- Only a select number of L-series tele lenses are supposed to have tripod detection and one of them isn't the 24-105, so that explains that one. I don't think the 300/4 is in that category either (nor is the 100-400 for example). Having said this, I see what you mean about this not being in the Canon manuals. What about the Canon Lens Works book? You do see reference to this here and there, e.g., at Adencamera.com you read for the 70-300L:
"The EF 70-300 f/4-5.6L IS USM features a function that prevents erroneous operation when the lens is mounted on a tripod or monopod."

But where do they get this information? It's not in the manual as far as I can see. I have read (maybe from Canon) that on lenses with tripod detection, the IS doesn't turn off but somehow changes function to deal with mirror slap. It must be somewhere in Canon's bumph.

BTW I've done some tests of this as well- 500/4 on locked down tripod, IS on (mode doesn't matter), Live view on and set to max. magnification, press the shutter release half way and the image drifts across the screen as the functioning IS attempts to correct, finger off shutter release and image jumps back to starting position. This test suggests that IS functions on a tripod as it does off but maybe there is still something subtly different about the way it is working while on a tripod.

This is from Canons website on the 500 f/4 IS

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This lens has also "camera shake correction mode 2" which corrects shaking of the viewfinder image when, for example, shooting a moving object, and a tripod can be used with the camera shake correction function ON.

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and here is the website http://www.canon.com/camera-museum/c..._4lis_usm.html

Don- That is IS mode 2 for panning. I think tripod detection is something different.

John,

I do have Canon lens works III, can you point me to the page where "tripod detection" is mentioned?

Thanks.

As far as I can see a reference to it is on page 187. It doesn't say much but here's the text:

"Tripod-compatible Image Stabilizer
When the first IS lenses were used with a tripod, the image stabilizer malfunctioned, requiring the photographer to turn off the image stabilizer function. However, the EF300mm f/2.8L IS USM and other new models in the super telephoto L type IS series are equipped with an image stabilizer that can be used with a tripod, which prevents malfunctioning. Since the system uses a vibration gyro to automatically detect when the camera is mounted on a tripod, the photographer can focus on the photograph without having to think about turning the stabilizer on and off. And when a monopod is used with any lens in the IS series, image stabilization is identical to that achieved during hand-held photography."

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Originally Posted by John Chardine

As far as I can see a reference to it is on page 187. It doesn't say much but here's the text:

"Tripod-compatible Image Stabilizer
When the first IS lenses were used with a tripod, the image stabilizer malfunctioned, requiring the photographer to turn off the image stabilizer function. However, the EF300mm f/2.8L IS USM and other new models in the super telephoto L type IS series are equipped with an image stabilizer that can be used with a tripod, which prevents malfunctioning. Since the system uses a vibration gyro to automatically detect when the camera is mounted on a tripod, the photographer can focus on the photograph without having to think about turning the stabilizer on and off. And when a monopod is used with any lens in the IS series, image stabilization is identical to that achieved during hand-held photography."

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Thanks John,
So in my case the system failed to "detect" that it was on tripod. I should mention that the shutter speeds that I was using were in the range of 1/250sec to 1/10 sec.
In a few occasions, I had also accidentally kept IS ON for a series of night shots, all of which came out like motion blurs as the IS had shifted the image during the long exposure. :w3

I just looked at my Canon EF 70-200 f/2.8 MKII manual. This is the latest telephoto so it should the latest IS module. Here is what it says on page 11:

" Using a tripod also stabilizes the image. However, depending on the kind of tripod and shooting conditions, sometimes it may be better to turn off the image stabilizer function "

What I make from this is that it is not a very reliable system so I will just play safe and keep mine OFF.

BTW, the new IS seems to have improved for handheld shots, now I can easily get sharp shots at 1/20sec at 200m.

Arash- the manual to my new 70-300L (fantastic lens BTW) has the same wording. This must be the boilerplate Canon is using for the new 4th gen. IS which both lenses have.

A note on the 300 f/4 L IS: it is an older IS version and the IS actually harms image sharpness when shutter speeds are on the order of or faster than 1/2000 second. I read this online many years ago and confirmed it with my own test. I have not observed the problem with the 500 f/4 or 300 f/2.8 L IS lenses.

Roger

Arash et al, my e-mail conversation with Canon's Chuck Westfall:

CW: Hi, Arthur:

re:

AM: My recollection is that you either told me the stuff below (or sent me a link that contained the info). Am I correct?

CW: My responses are indicated below:

AM: 1-The current super-telephoto lenses lenses (the 300 & 400 f/2.8L IS and the 500 & 600 f/4L IS) feature a tripod-sensing IS system...

CW: Yes.

AM:...that eliminates the vibration caused by both equipment shake and by mirror slap.

CW: I would say "minimizes" rather than "eliminates." You still need to use Silent Shooting Mode 1 or 2 in Live View on a 5D Mark II, 7D, 40D, 50D, or 60D for maximum stability due to the electronic 1st curtain shutter operation on those models.

AM: 2-Despite contradictory statements both on line and in many editions of the lens instructions, the IS switch on these lenses should be set at the “On” position at all times, even when the lens is mounted on a tripod.

CW: In most cases, we recommend using IS and other vibration-reducing techniques such as a cable release with mirror lock or Live View electronic 1st curtain shutter release for best results when these lenses are mounted on a tripod, but all of these techniques are optional. Also, keep in mind that IS must be fully operational for best results; that means it has to be running long enough to achieve maximum stability. When the IS super-telephotos are mounted on a tripod, it may take several seconds of operation before this level of performance is achieved. (You can see it through the viewfinder if you're paying attention.) IS cannot be achieved instantaneously. If it becomes necessary to release the shutter before IS can become fully functional, it may be better to shut it off.

AM: 3-With the four current super-telephotos it is best to set IS Mode 2 for all applications. Why? Because with these lenses IS Mode 2 performs exactly the same as IS Mode 1 when the lens is mounted on a tripod (except in one very rare instance: photographing a static subject from a moving vehicle).

CW: Tripod or not, Mode 2 IS makes most sense when there is a possibility of panning. When the lens is locked down on a tripod with no intention of moving it, there is no advantage to IS Mode 2. However, it's correct that IS Mode 2 acts like IS Mode 1 unless or until panning movement is detected.

AM: Is there a link to any or all of the above in any Canon documents or white papers on line?

CW: No.

Best Regards,

Chuck Westfall
Advisor, Technical Information
ITC Group Professional Engineering & Solutions I Division
Canon U.S.A., Inc.

Thanks Artie for posting this, appreciate sharing it with us. From CW statements looks like the system is not very effective and I think that is why Canon does not advertise it widely. I am not sure using live view or silent mode with several seconds of delay is best for avian photography, maybe for perched birds that are not moving but for action you will miss the shot :t3

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Originally Posted by Arthur Morris

...

CW: In most cases, we recommend using IS and other vibration-reducing techniques such as a cable release with mirror lock or Live View electronic 1st curtain shutter release for best results when these lenses are mounted on a tripod, but all of these techniques are optional. Also, keep in mind that IS must be fully operational for best results; that means it has to be running long enough to achieve maximum stability. When the IS super-telephotos are mounted on a tripod, it may take several seconds of operation before this level of performance is achieved. (You can see it through the viewfinder if you're paying attention.) IS cannot be achieved instantaneously. If it becomes necessary to release the shutter before IS can become fully functional, it may be better to shut it off. ...

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I think that this may help explain why some get bad test results.

Not long ago, I took some moon shots with my 500/f4 and a 1.4x TC, on the tripod, in live view and cable release. It was clear to see the moon move and shake when I pressed the release half way down, but in a second or two things cleared nicely and I released the shutter for a sharp shot. If you'd already focused and merely pushed the shutter without a pause at half way down, I think you'd likely get a poor result.

Arash, You are entitled to your opinion but as I said above, I have been using IS Mode 2 on a tripod with big lenses (600 f/4, 500/f4, and more recently 800/f5.6) since the 600 f/4 came out with great success, routinely making sharp images with teleconverters down to 1/60 sec and 1/30 sec. with the lenses alone. And I have worked at even slower speeds with the 800.

Not sure what your motivation is to say something negative about using IS on a tripod with Canon gear when by your own admission you do not use a long lens on a tripod....

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Originally Posted by David Stephens

I think that this may help explain why some get bad test results.

Not long ago, I took some moon shots with my 500/f4 and a 1.4x TC, on the tripod, in live view and cable release. It was clear to see the moon move and shake when I pressed the release half way down, but in a second or two things cleared nicely and I released the shutter for a sharp shot. If you'd already focused and merely pushed the shutter without a pause at half way down, I think you'd likely get a poor result.

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I agree that when working at very slow shutter speeds that waiting for the IS to calm down is best, bu I have never waited at all when photographing birds (as above) with my big lenses on a tripod. Is every image that I make sharp? No. But that is true for a great variety of reasons with operator error at the top of the list. I have never seen a long lens image ruined because IS was on while on a tripod.

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Originally Posted by Arthur Morris

Arash, You are entitled to your opinion but as I said above, I have been using IS Mode 2 on a tripod with big lenses (600 f/4, 500/f4, and more recently 800/f5.6) since the 600 f/4 came out with great success, routinely making sharp images with teleconverters down to 1/60 sec and 1/30 sec. with the lenses alone. And I have worked at even slower speeds with the 800.

Not sure what your motivation is to say something negative about using IS on a tripod with Canon gear when by your own admission you do not use a long lens on a tripod....

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Artie,

I assure you I did not have any negative intentions. I just stated that in my experience the system was not effective and my purpose was to learn what Canon's official recommendation was in this case and if I was missing something, thanks for posting CW's comments.

It is true that I don't use long lenses on tripod for bird photography, but I do use the 300 and occasionally the 500 for long distance landscape shots on tripod quite often. I sometimes make huge prints for clients and critical sharpness at pixel level is very important to me. Here is an example, it is 45 photos that have been stitched, made with the 5D2 and 300 f/2.8 on tripod.

http://ari1982.smugmug.com/Landscape...925_c6JnZ-O-LB

Any ways, thanks for sharing CW's response and also your experience.

Best

Quote:

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Originally Posted by arash_hazeghi

Here is an example, it is 45 photos that have been stitched, made with the 5D2 and 300 f/2.8 on tripod.

http://ari1982.smugmug.com/Landscape...925_c6JnZ-O-LB
Best

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Excellent job Arash. Looked at it on a 30" screen and you did an exceptional job with stitching.

Nikon here.
Using always VR (IS equivalent) below 1/500s tripod mode with 300 f2.8 and 600 f4 with or without TCs.
Above 1/500s I see no benefit, so I turn it off.
Handheld (300 with or without TCs) VR always on, active mode.

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Originally Posted by Sid Garige

Excellent job Arash. Looked at it on a 30" screen and you did an exceptional job with stitching.

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Thanks Sid, it took about 15 min to process, 900 Mega pixels of data! :w3

Super stitch Arash. What software?

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Originally Posted by John Chardine

Super stitch Arash. What software?

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http://www.ptgui.com/

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Originally Posted by Arthur Morris

CW:Also, keep in mind that IS must be fully operational for best results; that means it has to be running long enough to achieve maximum stability. When the IS super-telephotos are mounted on a tripod, it may take several seconds of operation before this level of performance is achieved. (You can see it through the viewfinder if you're paying attention.) IS cannot be achieved instantaneously. If it becomes necessary to release the shutter before IS can become fully functional, it may be better to shut it off.

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Hmmm. What does this imply for the "Bump Focus" technique for BIF? Seems like IS may be less effective for a second or so when the "bump" is initiated.

Roger

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Originally Posted by Roger Clark

Hmmm. What does this imply for the "Bump Focus" technique for BIF? Seems like IS may be less effective for a second or so when the "bump" is initiated.

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Good point ! IS or VR does take time to be effective. How about those who use the AF - button, do you use the AF-button (which does not trigger the IS/VR as far as I know) to bump focus, too? I suppose you can but not sure.

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Originally Posted by Desmond Chan

Good point ! IS or VR does take time to be effective. How about those who use the AF - button, do you use the AF-button (which does not trigger the IS/VR as far as I know) to bump focus, too? I suppose you can but not sure.

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I just checked this on my setup a moment ago. The IS on my Canon f/4 500mm activates when I press the AF-on button on my 1DM3 body. I can hear and feel the IS gyros activating whenever I press the shutter button halfway, or press the AF-on button. Part of the confusion that has pervaded this discussion has been that many have overlooked the 1-3 seconds of "boot-up" time that the Canon IS mechanism requires. Artie, Roger and Arash have correctly alluded to this, and Chuck Westfall also acknowleges it (though the Canon manuals are mute on the issue).

Try this: In Live View, with IS ON, press the AF-on, and you will hear the gyros kick in and see the monitor image wander slightly during IS boot-up, then settles down. The IS gyro mechanism takes time to get up to speed before it can effectively detect camera/lens movement, and the IS lens element wanders during that period.

In BIF and other rapid-response situations, if you anticipate impending action, you should press the shutter button halfway to activate the IS before you actually need to start firing. That way you can take full advantage of the IS without being affected by its boot-up instability.

For "bump" focusing, the IS gyros keep running for a second or two after you let go of the shutter button. This allows you to bump your focus but maintain continuity of IS operation.

As for the older IS lenses, like the 38-135mm, try making a 5-second exposure of a scene in low light with the IS turned on, using a tripod. The resulting image will look like you dragged a cat across it. That older system "hunts" around and never settles down, leaving an un-artistic blur trace (though beauty is in the eye of the beholder...). That's why it's "IS-OFF" for those lenses when using a tripod, especially for long exposures.

Craig Markham
http://www.cpmarkham.zenfolio.com

The purpose of IS for handheld flight photography is not to prevent blur in the photo from handshake or mirror slap. To achieve critical sharpness for flight shutter speed needs to be very fast and therefore the settling of the IS system is not an issue. The primary use of IS for hand held flight photography is to stabilize the rig so you can keep the bird in the center of the frame while panning. For BIF, I often raise the 500 rig right up to my sight rapidly and fire, there is not need to wait for the system to settle in this case.

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Originally Posted by arash_hazeghi

The purpose of IS for handheld flight photography is not to prevent blur in the photo from handshake or mirror slap. To achieve critical sharpness for flight shutter speed needs to be very fast and therefore the settling of the IS system is not an issue. The primary use of IS for hand held flight photography is to stabilize the rig so you can keep the bird in the center of the frame while panning. For BIF, I often raise the 500 rig right up to my sight rapidly and fire, there is not need to wait for the system to settle in this case.

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I'll challenge this. I say it is all of the above, not just "to stabilize the rig so you can keep the bird in the center of the frame." I've been testing imaging situations by attaching accelerometers to my cameras. I see +/- 0.2 to 0.5 g from the 1DIV mirror slap over 1/160 second sampling interval and extending for several tenths of a second, even when locked down on a tripod. This means velocities of 30 or so mm/second and 30 pixel movements over 1/160 second. The rates imply several pixel movement when shutter speeds are 1/2000 second. IS takes all that out. I'll have a newer accelerometer that samples at 320 Hertz in a few days. Many interesting results on long lens techniques and other situations, but a lot of data still to reduce too.

Roger

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Originally Posted by Craig Markham

For "bump" focusing, the IS gyros keep running for a second or two after you let go of the shutter button. This allows you to bump your focus but maintain continuity of IS operation.

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This is an important point. I would like to hear Doug chime in and hear if he practices and teaches this technique.

Roger

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Originally Posted by Roger Clark

I'll challenge this. I say it is all of the above, not just "to stabilize the rig so you can keep the bird in the center of the frame." I've been testing imaging situations by attaching accelerometers to my cameras. I see +/- 0.2 to 0.5 g from the 1DIV mirror slap over 1/160 second sampling interval and extending for several tenths of a second, even when locked down on a tripod. This means velocities of 30 or so mm/second and 30 pixel movements over 1/160 second. The rates imply several pixel movement when shutter speeds are 1/2000 second. IS takes all that out. I'll have a newer accelerometer that samples at 320 Hertz in a few days. Many interesting results on long lens techniques and other situations, but a lot of data still to reduce too.

Roger

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I am not sure if your method is valid and if it represents an experienced photographer actually holding up their rig while making photos. This is how Jim Neiger, Doug Brown and I photographed from Jim's boat in Florida and we have thousands of photographs that are razor sharp at pixel level (I delete the files that are not tack sharp at 100%). Of course most people struggle to make sharp flight shots and then try to blame the AF, IS etc. That's why Jim and Doug have very successful workshops to help people learn and develop these skills. The bottom line is we take these photographs routinely and they come out sharp and IS has never been an issue.


Here are two example of flight shot taken from Jim Neiger's boat, I am not sure if anything can get sharper than this.

Attachment 98846


Attachment 98847


Anyways, someone PMed me to weigh in here which just I did. I hope this answers their question.

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Originally Posted by arash_hazeghi

I am not sure if your method is valid and if it represents an experienced photographer actually holding up their rig while making photos. This is how Jim Neiger, Doug Brown and I photographed from Jim's boat in Florida and we have thousands of photographs that are razor sharp at pixel level (I delete the files that are not tack sharp at 100%). Of course most people struggle to make sharp flight shots and then try to blame the AF, IS etc. That's why Jim and Doug have very successful workshops to help people learn and develop these skills. The bottom line is we take these photographs routinely and they come out sharp and IS has never been an issue.

Here are two example of flight shot taken from Jim Neiger's boat, I am not sure if anything can get sharper than this.

Anyways, someone PMed me to weigh in here which just I did. I hope this answers their question.

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Arash,
I was not challenging that people can't get sharp images of BIF. I was simply stating that IS does more than just the one thing "to stabilize the rig so you can keep the bird in the center of the frame." I didn't say IS is a problem. I said IS helps all the vibrations, not just one thing. There is ample evidence that many people can get impressively sharp images of birds in flight hand held. But I would bet most have IS on. Are you implying that that you, Jim, and Doug never use IS?

When the shutter button is pressed, the mirror flips up, hits the top and that sets up a resonant vibration that takes more than a second to calm down, and under normal photography in rapid fire BIF photography the shutter openson the order of 0.05 second from the mirror hitting the top if its swing (1D4). So the shutter is opening at peak vibration. Hands actually help dampen the magnitude of the vibration but does not dampen it completely. Evidence of this is I'm shure everyone can feel and hear the mirror slap of the camera in action. That vibration sets up a torque on the lens + camera, and IS compensates for it and does a very good job. The vibration rates I'm seeing says one needs to be well above about 1/2000 second to reduce the possibility of blur from the 1DIV mirror slap with a long telephoto (e.g. 500 mm+) if IS is off. As shutter speed drops below about 1/2000 second probability of smear from mirror slap increases if one does not have IS on. Above 1/2000 second the probability reduces. These are preliminary and I may modify these results when I get my higher rate accelerometer. But I think these numbers agree with experience in the field.

Roger

Just wondering that shooting small birds with my 600mm and 7D on tripod IS on at a burst of #3 shots it seems that image #2 is usually the sharpest especially compared to image #1. After reading comments wonder if IS reving up accounts for that or some other factor.
Of course not always the fact but happens enough for me to start to notice. No real way to check in retrospect but I think I will experiment with IS on and IS off. I still believe IS helps me more than it hurts me on tripod with 600mm !

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Originally Posted by ChasMcRae

Just wondering that shooting small birds with my 600mm and 7D on tripod IS on at a burst of #3 shots it seems that image #2 is usually the sharpest especially compared to image #1. After reading comments wonder if IS reving up accounts for that or some other factor.
Of course not always the fact but happens enough for me to start to notice. No real way to check in retrospect but I think I will experiment with IS on and IS off. I still believe IS helps me more than it hurts me on tripod with 600mm !

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I think Charles' casual observation about the IS settling during continuous firing is correct. Shooting a burst of continuous frames gives the IS time to fully engage and the later images will probably benefit.

I live and do much of my photography in the Pacific Northwest. We do not get the year-round blazing sun of Florida, East Africa or India. Most winter days here are heavily overcast with low sun, and in summer, the intense clear skies and foliage produce dappled high-contrast scenes. Consequently, 1/2000 sec shutter speeds are not often feasible here, especially during the winter months. This means that even at wide-open apertures and ISO800, shutter speeds are often in the 1/15 to 1/350 range, even with flash extension. Making good decisions about using IS is even more critical here than it is for our tropical counterparts.

I realize that in strong light, blazing away on continuous shutter at 1/2000 on the chance of catching the perfect pose can work, especially in the hands of (ahem) an experienced photographer. Personally, I usually prefer to time firing single shots with the rhythms of the subject. Fact is that even at 10 FPS, simply holding down the button can completely miss "the moment". I make an exception to this for birds with rapid wing beats, erratic flight or other rapid unpredictable motion that cannot be timed or anticipated. Good flight tracking and steadiness skills are required for BIF, but whether you are a "sniper" or a "machine-gunner", good choices about when and how to use IS increase your chances of capturing a fine image.

Craig

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Originally Posted by Craig Markham

I think Charles' casual observation about the IS settling during continuous firing is correct. Shooting a burst of continuous frames gives the IS time to fully engage and the later images will probably benefit.

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Regardless of the reason, it seems to me that many have found out that, if you have to shoot (any subject) at slow shutter speeds but without any supporting around, shooting a burst of frames likely gets you at least one of the shots sharp. Of course I don't think it works for 1-sec-exposure shot or the like. And I'm not sure if they are talking about with the use or without the use of IS/VR.

Arash, you are right! They do not get any better or sharper than those two images. Interesting discussion; lovely image additions to the discussion.

Quote:

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Originally Posted by Roger Clark

Arash,
I was not challenging that people can't get sharp images of BIF. I was simply stating that IS does more than just the one thing "to stabilize the rig so you can keep the bird in the center of the frame." I didn't say IS is a problem. I said IS helps all the vibrations, not just one thing. There is ample evidence that many people can get impressively sharp images of birds in flight hand held. But I would bet most have IS on. Are you implying that that you, Jim, and Doug never use IS?

Roger

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I use IS pretty much all the time. I set it ON mode 2. I have tried it both ways, on and off, and at the shutter speeds that are typical for me, it seems to make no difference if the IS is on or off. At slower shutter speeds, I think IS on is helpfull for flight images. I think the speed that IS starts to help at is about 1/1250 or 1/1000 depending on conditions. IS tends to help when SS is slower than that.

Jeez, I have not been here for a while and had forgotten that I had started this thread. I have skimmed it and there is lots of great stuff above. As one who formerly left IS on all the time no matter the situation I had my eyes opened big times the other day. I learned that when making really long exposures on a tripod with a big lens, one second or more, for example, that IS absolutely needs to be turned off.... Learn all the gory details in Long Lens/Long Exposure/Image Stabilization Lesson Learned.

Quote:

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Originally Posted by Arthur Morris

As one who formerly left IS on all the time no matter the situation I had my eyes opened big times the other day. I learned that when making really long exposures on a tripod with a big lens, one second or more, for example, that IS absolutely needs to be turned off.... L

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Hey Artie,
this is what I was talking about :S3: I have occasionally seen it screw up as high as 1/20-1/30sec with the 500.

Got it. I have always done well at those shutter speeds are at least I think that I have. But heck, I am always on a tripod and you are always off it :)

I'm attaching a some plots of an accelerometer attached to a camera to illustrate the vibrations due to framing during imaging. In the attached plot, I did two tests. My accelerometer measures acceleration in units of g (acceleration due to gravity = 1) from which velocity and position as a function of time can be derived. My accelerometer samples at 320 Hz. These data have been high pass filtered, meaning they show higher frequency vibrations only, and not movement due to panning.

First I tightly held the Canon 1D Mark IV with 500 mm f/4 L IS attached tightly in my arms and held tightly to my chest. With one hand on the camera and pushing the camera tightly to my chest and a finger on the shutter button, I fired two short sequences at 10 frames per second. This test illustrates my ability to dampen high frequency vibrations caused by mirror movement and is shown as the red curve in the figure. Mirror slap causes vibration up to about 25 microns (about 5 pixels) in 1/320 second.

The second test was a bird in flight test. I ran 8 tests and this sequence is the best (lowest vibrations). In this test, I held the 500 with one hand with my elbow tucked to my side. With my second hand, I held the camera tightly to my cheek and firmly in my hand with my index finger on the shutter button. I panned and during panning, I fired two sequences at 10 frames per second (blue line in the plot). The fact that the two sequences have timing where firing frames occurs at nearly the same time is a coincidence.

The BIF results show vibrations of up to almost 80 microns (the 1D mark IV has 5.7 micron pixels) in 1/320 second, or over 13 pixels. The peaks are caused by mirror slap and there is usually a bounce of the mirror also recorded in a second peak. Then the camera settles down a little when the shutter opens, but during the actual imaging period, vibrations of over 30 microns occur in 1/320 second (over 5 pixels).

The vibrations recorded are limited by the accelerometer and the vibrations at 1/1,000 second (kilohertz) are likely higher. But even assuming these numbers are the maximum, and that the vibrations scale linearly, a 5+ pixel shift in 1/320 second translates to about 1.7 pixel shifts at 1/1,000 second exposures, and 0.8 pixel shift at 1/2,000 second exposures.

Image stabilization does a great job of producing sharp images. This data says that the IS is removing the effects of these vibrations at least for exposure times as fast as 1/2,000 second and that one should use IS up to at least 1/2,000 second.

A side note. I found an interesting effect on hand holding. When hand holding and pointing in one direction at a static subject, I produced more vibrations, but when I started panning, those body-induced vibrations smoothed out. So I would say hand held panning works better than static hand held imaging.

Roger

And here is an enlargement showing the vibration details.

Very interesting, Roger! I am not sure how much this really tells us about its effect on producing images in the real world though. The real world just has too many variables to ever really know. I guess thats one of the things that make photography so fascinating.

I found your comment about IS being effective up to 1/2000 to be interesting. Perhaps I'm not seeing a difference until 1/1250 because the difference is so small at 1/1600 or 1/2000 that its not noticible.

Quote:

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Originally Posted by Jim Neiger

Very interesting, Roger! I am not sure how much this really tells us about its effect on producing images in the real world though. The real world just has too many variables to ever really know. I guess thats one of the things that make photography so fascinating.

I found your comment about IS being effective up to 1/2000 to be interesting. Perhaps I'm not seeing a difference until 1/1250 because the difference is so small at 1/1600 or 1/2000 that its not noticible.

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Hi Jim,

Certainly, the differences will be smaller at 1/2000 second versus 1/1000 second, but I bet if you did a BIF session with 1/2000 second exposures, 100 exposures with IS on and 100 with IS off, you would have a higher percentage of critically sharp images in the IS on set. The difficulty in such a test is BIF photrography is so variable depending on what the birds are doing, so "real world" test can be biased unless the sample set is very large. Controlled tests, like the one I showed can tell the real story. But, if you have "vice grip" like hands, you may be able to dampen the vibrations better than I can, so would see less effect. So my test is strictly valid for me. I did the hold tight to the chest test to find the probable lower bound of what is possible, to show there was still a significant amount of induced vibrations. Note: 50 microns is really small: 0.002 inch, and one pixel would be a movement of 0.00022 inch. I doubt anyone can hold a 1DIV camera to within 0.00022 inch with the mirror swinging up and down at 10 frames per second. It is actually amazing how well IS works, and to impressively small tolerances!

Roger

I guess for me the bottom line is that either way it doesn't affect my SOP which is to leave IS on mode 2 all the time when shooting BIF. If I always have it on when shooting bif, it doesn't make any difference to me if it becomes effective at 1/1250 or 1/2000, I'm covered either way. :S3:

Very good Roger. There is nothing like applying some good science to a question like this. As you were measuring acceleration at the camera body, I assume the actual movement of the projected image on the sensor depends on the focal length of the lens would it not?

Do you think the movement amplitudes you were seeing are large enough to affect the ability of the AF system to do it's job?

Quote:

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Originally Posted by John Chardine

Very good Roger. There is nothing like applying some good science to a question like this. As you were measuring acceleration at the camera body, I assume the actual movement of the projected image on the sensor depends on the focal length of the lens would it not?

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Hi John,

Thanks, John.
I computed movement of the entire camera, so in linear units of camera movement, it is independent of focal length. But the angular movement that the IS system needs to compensate for vibration is dependent on focal length. Interestingly, the longer the focal length, the less the in-lens IS angular position needs to move.

Quote:

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Originally Posted by John Chardine

Do you think the movement amplitudes you were seeing are large enough to affect the ability of the AF system to do it's job?

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I think it could be a negative factor if one were not using IS. With IS on, the stabilization helps both the image and the AF system (as you know). The AF system is taking its measurements when the mirror is down, which is in between the mirror down position and the mirror up at the start of the next frame, and that time interval seems to be very short. That period is also when the maximum vibrations are occurring, so IS on certainly helps stabilize the image for AF measurement and tracking.

Over the next few weeks/months I'll test tripods, bean bags, and long lens technique and mirror lock-up.

Roger

I am not sure if this methoid is valid. The readings from accelerometer seem extremely noisy and the peaks are just spurious spikes, I am not sure it is possible to enumerate such readings and draw conclusions.


An image shift of 80 microns! at 1/320 sec will make the image as soft as a drunk man's dream :S3: I rountinly make tack sharp images with lenses that don't even have IS (like the 200mm f/2) at 1/320 and down to 1/100 sec easily. I am sure most poeple can do this. I think the best rule of thumb for determining the speed form which IS becomes effective is the 1/EFL rule that is recommended by the manufactruers. Maybe a bit more consevertive if the rig is too heavy or if someone has weak/shaky hands. If you can't make sharp images say at 1/1000sec with the 500mm wiht IS OFF most likely it is the physical limitation of the photographer themesleves.


Anyways, not much more information to add I guess it is best to stick with whatever works for you.

Last note from Chuck Westfall:

As far as official Canon documentation is concerned, "tripod sensing IS" is an undocumented feature of the 1st generation IS super telephoto lenses. The closest reference I've seen in print appears in EF Lens Work III. The current version (Edition #13, released in March, 2011) states the following:

Tripod- and monopod-compatible Image Stabilizer

"The EF300mm f/2.8L IS II USM and other IS lenses automatically prevent accidental activation of image stabilization when used on a tripod. This eliminates the need for having to manually turn the Image Stabilizer off. With the EF200mm f/2L IS USM, EF800mm f/5.6L IS USM and various other EF lenses, image stabilization reduces minor blurring caused by camera shake and other factors when shooting with a tripod. And when a monopod is used with any lens in the IS series, image stabilization is identical to that achieved during hand-held photography."

The group of "various other EF lenses" includes the 1st generation IS super telephotos as well as the EF70-200mm f/2.8L IS II USM and the EF70-300mm f/4-5.6L IS USM, even though they are not explicitly mentioned.

Chuck

Quote:

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Originally Posted by arash_hazeghi

I am not sure if this methoid is valid. The readings from accelerometer seem extremely noisy and the peaks are just spurious spikes, I am not sure it is possible to enumerate such readings and draw conclusions.

An image shift of 80 microns! at 1/320 sec will make the image as soft as a drunk man's dream :S3: I rountinly make tack sharp images with lenses that don't even have IS (like the 200mm f/2) at 1/320 and down to 1/100 sec easily. I am sure most poeple can do this. I think the best rule of thumb for determining the speed form which IS becomes effective is the 1/EFL rule that is recommended by the manufactruers. Maybe a bit more consevertive if the rig is too heavy or if someone has weak/shaky hands. If you can't make sharp images say at 1/1000sec with the 500mm wiht IS OFF most likely it is the physical limitation of the photographer themesleves.

Anyways, not much more information to add I guess it is best to stick with whatever works for you.

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Arash,

First, the 80 micron spike is the mirror slap, not the blur during exposure. During exposure, the vibration is in the 20 to 30 micron range.

One can not extend the data to other lenses without more data. The major movement of the camera is caused by the torque of the mirror swinging up and down. Attach a small lens and fire a few frames and this torque is easily felt on the 1D4. But on a big lens, the mass is large so the system has too much inertia so translates into significant movement because the center of mass is so far from the camera. This translates to a rotation of only about 1.3 arc-minutes. Try holding a laser pointer to that accuracy--it is difficult for most people. The camera on a smaller lens can rotate more with less translation of the sensor, and with the shorter focal length, less impact on image quality.

Note too that the 1D4 has the highest torque and mirror slap in the Canon line due to the 10 frames per second. Other cameras should have lower vibrations.

Regarding noise, I plotted the red line to show the accelerometer has inherently low noise compared to that in the BIF test. When the camera is not firing, the vibration data shows peaks of only 10 to 15 microns, but the second plot shows that those peaks are much lower frequency, and indicates I would be getting sharp images (movements well under 1 pixel) at exposure times as long as 1/100 second if there were no vibrations from the mirror.

Finally, regarding the 1/focal length rule, it was derived in film days. Today's digital cameras have higher focal plane resolution so the rule needs modification, like 1/(x*focal length), where x is a larger number for cameras with smaller pixels. When pixel size is about 8 microns, x should be about 1, and for the 7D with 4.3 micron pixels, it would be closer to 2. The 1D4, x ~ 1.4, or easier to remember, 1.5.

Roger