Use of IS on canon 100-400L IS lens and tripod

[Jon]

I recently added to a thread but I cannot remember where it was but I have found this which supports my personal view of leaving IS switched on even when using a tripod, Jon

Based on my own personal testing and
observation, as well as a personal consultation with one of Canon
Inc.'s chief executives in the Lens Division, these lenses effectively
have 2 IS modes *within Mode 1.* The decision on which mode will be
used is made by the equipment, not the photographer, based on an
evaluation of the degree of detected movement, as follows:

A. When the lens is mounted on a steady tripod and the shutter button
is pressed halfway, the IS begins to operate immediately and the image
in the viewfinder goes through a very slow vertical shift for about 1
second. After that, if the shutter button continues to be pressed
halfway, the IS mechanism automatically goes into a special mode which
is designed to detect and correct for mirror slap and shutter movement
at slow shutter speeds. Based on my personal testing, it does this job
spectacularly well. Close examination of results from shooting tests
definitively proves that there is no advantage to be gained by
shutting off IS, or even by locking the mirror prior to exposure.

B. When the lens is mounted on a monopod or hand-held *and* the gyro
sensors detect movement exceeding a certain rate, the IS mechanism
switches into its conventional correction mode which is designed to
compensate for relatively gross and/or erratic lens movement.

So, what you're seeing when you loosen the ball head and start moving
the lens is essentially an automatic switchover from "tripod IS" to
"conventional IS."

[JeffH]

That's very interesting Jon but did your Canon contact offer any explanation as to why the 100-400IS lens booklet says IS should be switched off for shots on a tripod?

I've now received conflicting advice on this point from several sources and in his review of this lens in this month's Digital SLR User magazine, professional wildlife photographer Ben Hall says (in relation to using the lens on a tripod) - "...it's as well to be aware that when there is not enough motion for the IS system to detect, it can result in an electronic 'feedback loop', which can actually create a soft image. With this in mind it's important to switch the IS off when the camera is mounted on a tripod, although the very latest third generation IS is said to have overcome this problem".

Don't know about you but I'm as confused as ever

Jeff

[Raffman]

This is an interesting one as everything I have ever read has stated that as a 1st generation IS system you should keep IS off whilst on a tripod unless its perhaps really windy. I'll have to give it a bash tomorrow.

Raff

[danpen]

I tend to forget to switch the IS off when using a tripod and have not seen anything that's made me regret that. I use both the 100-400 and the 20-200, the latter I realise has the newer IS that should be OK but as I said I've never seen any problems with either.

Mind you I don't examine each of my shots at pixel level and probably wouldn't remember which ones had IS on a tripod and which didn't, but I would notice if it made a substantial difference.

[Jon]

Originally Posted by JeffH

That's very interesting Jon but did your Canon contact offer any explanation as to why the 100-400IS lens booklet says IS should be switched off for shots on a tripod?

I've now received conflicting advice on this point from several sources and in his review of this lens in this month's Digital SLR User magazine, professional wildlife photographer Ben Hall says (in relation to using the lens on a tripod) - "...it's as well to be aware that when there is not enough motion for the IS system to detect, it can result in an electronic 'feedback loop', which can actually create a soft image. With this in mind it's important to switch the IS off when the camera is mounted on a tripod, although the very latest third generation IS is said to have overcome this problem".

Don't know about you but I'm as confused as ever

Jeff

Jeff the manual for the IS 100-400L has not been updated in respect of the IS, apparently Canon are well known for not updating manuals. The quote I gave from someone high up in Canon inc.
The use of IS2 not recommended, the IS system keeps making the motor move because it is looking for movement that isn't there. IS1 may be used on a tripod if you have a more recent lens. I do not know what constitutes a more recent lens. I bought mine about 14 months ago but I don't know if it was old stock or not, apparently it is possible to tell by the serial number, I recall reading it in EOS Mag once.
To cut to the chase I leave IS1 on permanently and when I can remember I use IS2 if I am hand holding for flight shots. Jon

[Jon]

Geoff and Raffman, now I am also getting more confused by contradictory advice, this is what I found on the Canon CPS/ProSupport web site:
The instruction sheets with IS lenses say to turn the IS function OFF when using a tripod. I have heard other photographers argue the opposite. What is the correct advice?
The answer depends on which type of IS lens you're talking about. With the IS super-telephotos (300/2.8L IS, 400/2.8L IS, 500/4L IS and 600/4L IS) as well as the 28-300/3.5-5.6L IS, 70-200/2.8L IS, 70-300/4.5-5.6 DO IS and the 400/4 DO IS, it's OK to leave IS turned on when the lens is mounted on a tripod. For all other current IS lenses (28-135/3.5-5.6 IS, 75-300/4-5.6 IS, 100-400/4.5-5.6L IS, and 300/4L IS), it is much better to shut off the IS function when the lens is mounted on a tripod.

Short explanation: the IS mechanism operates by correcting shake. When there is no shake, or when the level of shake is below the threshold of the system's detection capability, use of the IS feature may actually add unwanted blur to the photograph, so you should shut it off in this situation.

Longer explanation: remember that the IS lens group is normally locked into place. When the IS function is active, the IS lens group is unlocked so it can be moved by the electromagnetic coil surrounding the elements. When there's not enough motion for the IS system to detect, the result can sometimes be a sort of electronic feedback loop, somewhat analogous to the ringing noise of an audio feedback loop we're all familiar with. As a result, the IS lens group might move while the lens is on a tripod, unless the IS function is switched off and the IS lens group is locked into place.

For most hand-held work, leave the switch on; for tripod work, shut it off, as noted in the instruction book.

But these recommendations above do not apply to the 28-300/3.5-5.6L IS, 70-200/2.8L IS, 70-300/4.5-5.6 DO IS, 300/2.8L IS, 400/2.8L IS, 400/4 DO IS, 500/4L IS, and 600/4L IS. With previous IS lenses, it was necessary to turn off the Image Stabilizer when using a tripod because it might operate incorrectly. But the Image Stabilizer installed on these IS lenses has an additional function that prevents improper operation when using a tripod. It also corrects camera vibration caused by slow shutter photography when using a tripod: a common problem with super-telephoto lenses. About one second after the shutter is pressed halfway, the unit automatically determines that a tripod is being used from the output of a vibration gyro.

These lenses effectively have two IS modes within Mode 1. The decision about which mode will be used is made by the equipment, not the photographer, based on an evaluation of the degree of detected movement, as follows:
When the lens is mounted on a steady tripod and the shutter button is pressed halfway, the IS begins to operate immediately and the image in the viewfinder goes through a very slow vertical shift for about 1 second. After that, if the shutter button continues to be pressed halfway, the IS mechanism automatically goes into a special mode which is designed to detect and correct for mirror slap and shutter movement at slow shutter speeds. Based on tests, it does this job spectacularly well. Close examination of results from shooting tests definitively proves that there is no advantage to be gained by shutting off IS, or even by locking the mirror prior to exposure.
When the lens is mounted on a monopod or hand-held and the gyro sensors detect movement exceeding a certain rate, the IS mechanism switches into its conventional correction mode which is designed to compensate for relatively gross and/or erratic lens movement.


If you want the best possible results when working from a tripod with an IS lens that supports 'tripod IS', you have to let the mechanism operate for at least 1 second before shutter release. If you're really serious about it, use an eyepiece magnifier to confirm that the IS mechanism has settled down, and also use a remote switch so you don't have to touch the camera body when releasing the shutter.

If you release the shutter too early for the IS mechanism to react and your shutter speed is slow enough, you will probably get some image blur.

It is worth noting that Canon's Image Stabilization works regardless of the focusing mode in use, whether it's One Shot, AI Servo or Manual.

My interpretation would be that if the camera is on a tripod that is locked i.e. guaranteed almost rock steady and you use a remote release of some kind , then under these circumstances you should turn off IS with the 100-400L IS lens.
However in practice I am lazy and I use a tripod when possible but I do not lock the head as I may have to move it regularly, under these circumstances I do use IS and as far as I can see it works. I suppose you will have to see if your lens keeps hunting with IS on then if it does, simply turn it off. Jon

[JeffH]

Jon,

Thank you for that very comprehensive explanation and for taking the time and trouble to research and post it - much appreciated.

Jeff

PS. How are those pond plans coming along? Do get in touch when you're ready to go and if I can be of any help.