dandev wrote:
....3 IS modes. 1-All the time, 2- Panning, and 3 - only on when shooting. (And there is Off) Does anyone have any experience with which is best? I use back-button focus on my Canon 5D lll in AI servo mode. Mostly shooting animals, birds, sports. About 50/50 hand held vs. tripod. If you use mode 3 -do you have to turn your IS Off when using a tripod?
Thanks....
There is no single "best" mode. It depends upon what you are doing and how you want the IS to work (how you want the image rendered, in some cases).
Mode 1 - Standard dual axis stabilization. Both horizontal and vertical movements are being corrected. Starts and runs normally with half press of the shutter release button or when the AF On button (or other assigned button) is pressed during BBF. Both the image in the viewfinder and the image being captured are stabilized. I usually like the viewfinder image being stabilized, so this mode is the one I use most of the time.
Mode 2 - Single axis "panning stabilization". Only movement along the vertical axis is corrected. And it doesn't matter the orientation of the camera. That's detected and the stabilization changes accordingly. This mode is used when panning with a slower shutter speed, where you are trying to deliberately blur movement in the horizontal axis and don't want the stabilization counteracting your efforts. It starts and runs the same way as Mode 1. And it effects both the viewfinder and the image.
Mode 3 - Instant dual axis stabilization, same as Mode 1, except this only starts and runs during the actual exposure. Unlike Mode 1, it doesn't start up as soon as you half press the shutter release (or press a button on the back of the camera using BBF). Stabilization doesn't occur until during the actual exposure, which can be a fraction of a second, so this lens' stabilization must be extremely fast acting. This mode basically doesn't effect the viewfinder image... only the image being captured. It also might be useful in extremely quiet situations, where the slight noise of the IS running would be heard (of course, your DSLR's shutter and mirror are still making noise). In certain situations, the IS stabilizing the viewfinder image might be unnecessary or unhelpful, too. Mode 3 also might save a little battery power in some situations, though in my experience IS doesn't draw a lot.
The 100-400 II is the least expensive lens to have this advanced form of IS, which is good for 3 to 4 stops of effectiveness (varies with user capabilities and other factors). The "II" series "super telephotos" (300mm f/2.8, 400mm f/4, etc.) are the other lenses that have Mode 3/Instant IS.
Honestly, I leave mine set to Mode 1 mostly, occasionally use Mode 2 in special panning situations, rarely if ever use Mode 3.
I also leave this lens' IS on pretty must all the time... tripod, monopod or hand held. For one thing, most of the time when on a tripod I'm using a "loose gimbal" technique with telephoto lenses like this, so there's still plenty of movement and work to keep the IS happy and working well. There's certainly plenty of movement when using a monopod or hand holding it. Also, the 100-400 II has "self-detecting" IS that shuts itself off in situations where there is no movement, such as when locked down solidly on a tripod.
The original 100-400 is one of five Canon lenses with IS that need it manually turned off, in the total absence of any movement, such as when locked down on a tripod. Forget to turn it off and you'll see the viewfinder image "go crazy" with movement... no harm done unless you take a shot with it.... simply turn it off if you see that happen. Not to be confused with the slower "drift" of images that occurs with IS.
But, again, that's not a problem with the II... it self-detects and turns off IS itself, when there's no movement at all to correct.
The slower "image drift" that occurs with all IS lenses, but has no effect on images themselves... can be an issue in certain situations. For example, if you're shooting video or are working with a very critical composition. In those cases, you may wish to turn off IS.
Canon user manuals say to turn IS off when using a tripod. But that's really just to save a little battery power (But not much, in my experience... I see little difference in shots-per-charge using two identical cameras: one with an IS lens, the other without).