Canon Image Stabilization

[mercphoto]

I know that many of Canon's IS lenses can't use IS when on a tri-pod. I also know that a handful of those lenses have a new IS mode that, when it detects its on a tri-pod, uses the IS to counter the effects of mirror-slap.

Is the 70-200/2.8L/IS lens one of those lenses?

[DoctorIt]

That's one of the newest technology lenses, so if this were the case, then yes. But how can IS help with mirror-slap? I don't understand the geometry on that...

It's fun to leave the IS turned on with my 28-135 w/tripod. The whole image moves in the viewfinder :D (probably not too good for IS, but i've forgotten more than once).

[fish]

Your best bet is probably to enable mirror lockup (MLU), because I think that function is only available on the superteles, like the 400 IS and up.

from http://www.digitaljournalist.org/issue0007/cameracorner.htm:
So, what's the big deal with the stabilized lens? Well, if I had shot a normal 400mm lens at 1/30th, even on a tripod, I would have been very lucky to get a sharp frame. Just the shutter bounce at that focal length would have been enough to blur the picture. Canon has added a new function that allows the IS super-telephoto lens to detect whether or not it's being used on a tripod. If it is, the lens goes into a new super-sensitive IS mode that's capable of correcting even subtle movements such as the slap of the camera's reflex mirror prior to exposure. This is precisely the capability I needed.

[mercphoto]

Your best bet is probably to enable mirror lockup (MLU).

Man I feel stupid... :(

[fish]

To add to the confusion, I just read this in the Canon Lens Brochure:

...the EF 300mm f/2.8L IS USM, EF400mm f/2.8L IS USM, EF 500mm F/4 IS USM, and EF 600mm f/4L IS USM lenses have a mechanism that prevents having the Image Stabilizer turnedon while the lens is mounted on a tripod.

So I assume this means that they switch to the supersensitive IS mode that way. :dunno

[DoctorIt]

To add to the confusion, I just read this in the Canon Lens Brochure:

...the EF 300mm f/2.8L IS USM, EF400mm f/2.8L IS USM, EF 500mm F/4 IS USM, and EF 600mm f/4L IS USM lenses have a mechanism that prevents having the Image Stabilizer turnedon while the lens is mounted on a tripod.

So I assume this means that they switch to the supersensitive IS mode that way. :dunnoIt's all a gimmick .... :lol3

[wmsnyder]

[QUOTE=fish]To add to the confusion, I just read this in the Canon Lens Brochure:

...the EF 300mm f/2.8L IS USM, EF400mm f/2.8L IS USM, EF 500mm F/4 IS USM, and EF 600mm f/4L IS USM lenses have a mechanism that prevents having the Image Stabilizer turnedon while the lens is mounted on a tripod.

This is from Canon's EF Lens Work III book. The lens uses a vibration gyro to automatically detect when it is mounted on a tripod.

[pathfinder]

[QUOTE=fish]To add to the confusion, I just read this in the Canon Lens Brochure:

...the EF 300mm f/2.8L IS USM, EF400mm f/2.8L IS USM, EF 500mm F/4 IS USM, and EF 600mm f/4L IS USM lenses have a mechanism that prevents having the Image Stabilizer turnedon while the lens is mounted on a tripod.
I think the 400mmDO IS has the same position 2 IS also.

This is from Canon's EF Lens Work III book. The lens uses a vibration gyro to automatically detect when it is mounted on a tripod.


And yet when I shoot the 300mmF2.8 from a bean bag I leave the IS on in position 1, and it seems to continue to stablize the image as long as I have the shutter depressed halfway. And I suspect a good bean bag mount is more stable than a monopod in field usage. Even on a tripod, most long lenses are not locked into position but are gimbled on a Wimberly head or a Wimberly Sidekick. Thus they are not truly held sationary even on a tripod. :dunno

[fish]

I think the 400mmDO IS has the same position 2 IS also.
So mode 2 is just for panning, as it only corrects vibrations and shaking in the direction at right angles to the camera's panning movement. Mode 1 corrects all vibrations no matter whether the camera is being held horizontally, vertically, or at an angle.




And yet when I shoot the 300mmF2.8 from a bean bag I leave the IS on in position 1, and it seems to continue to stablize the image as long as I have the shutter depressed halfway. And I suspect a good bean bag mount is more stable than a monopod in field usage. Even on a tripod, most long lenses are not locked into position but are gimbled on a Wimberly head or a Wimberly Sidekick. Thus they are not truly held sationary even on a tripod. :dunno
Why wouldn't you use the supplied tripod ring? :scratch

[pathfinder]

So mode 2 is just for panning, as it only corrects vibrations and shaking in the direction at right angles to the camera's panning movement. Mode 1 corrects all vibrations no matter whether the camera is being held horizontally, vertically, or at an angle.

Yes, that is my understanding. I do not know where this stuff about IS correcting mirror slap came from. I do know you want to avoid 1/4 through 1/60 with long glass( >300mm) if you can because of vibrations from the mirror. Some SLRs have better damping of mirror slap than others. It is one of the things that no one mentions that is included in the 1 series cameras, for instance.


Why wouldn't you use the supplied tripod ring? :scratch

Not sure I understand this question, Fish? The tripod ring plate IS mounted in the Wimberly gimbal head or a Wimberly Sidekick. The Wimberly gimbal head is used for 600mm and up lenses and is large and heavy to carry around. From the Wimberly website www.tripodhead.com
Wimberly gimbal head http://tripodhead.com/images/wh-contrast-bw-color.jpg

The Sidekick is a smaller cantilever mount that slides vertically into an ArcaSwiss plate on a ball head on a tripod. The tripod ring in your lens is rotated horizontally and the lens then mounted as shown in this image of a Sidekick. I have used a Sidekick since last year when I went to Bosque del Apache and it is going back with me in a few weeks again.
http://tripodhead.com/images/sk-contrast.jpg http://tripodhead.com/images/sk1.jpg

Large telephotos require good tripods and and good tripod heads to allow their eficient and effective use. The longer the glass, the less the ability to handhold - IS notwithstanding. I have used the Wimberly Sidekick on an Arca Swiss ballhead for most of my telephoto shots and recommend it highly. It is very well made.