MakisM1 wrote in post #15848441
When we talk about older lenses, we talk about pre-1995 designs. The post-1995 lenses can have the IS on, since they are designed to sense the tripod.
Sorry to say, but that's not true...
In fact, in 1995 there were no IS lenses for SLRs. The first IS EF-mount lenses were the 28-135 in 1998 and the 300/4 in 1997, if memory serves. There might have been one or two before, but not much earlier than 1997.
Whether or not an IS lens needs to have the IS turned off when locked down on a tripod is determined by the sophistication of the IS system in the lens, has little to do with the lens' age.
The list of lenses (hasn't been updated by Canon in years, so is only a partical list) that need it turned off when locked down on a tripod happen to include some of the older, less sophisticated, but also include some much newer lenses...
TURN IT OFF:
While the list of lenses that it can be left on (IS senses lack of movement and turns itself off) includes lenses intro'd as early as 1999...
OKAY TO LEAVE IT ON:
70-200 (all versions with IS, including as early as 2001)
300/2.8 (both w/IS)
400/2.8 (both w/IS)
500/4 (both w/IS, inlcuding the first of the super teles with IS, March 1999)
600/4 (both w/IS)
UNKOWN, BUT PROBABLY SAFE TO LEAVE ON:
UNKOWN, BUT PROBABLY NEED TO TURN OFF:
18-55 (all versions with IS)
HAVE ABSOLUTELY NO IDEA EITHER WAY:
OP, looking at your gear list, you appear to only have two IS lenses and both are on the OKAY TO LEAVE ON list... Well, actually the 100L macro isn't on any official list yet.... But it's hard to imagine Canon wouldn't assume a macro lens is going to spend it's fair share of time on a tripod, so would put tripod-sensing IS in it. I think there are no worries for you either way, even if your tripod is solidly locked down.
However for future reference, I would consider a lens being used on an "unlocked" tripod - such as panning with moving subjects and/or on a gimbal mount of some sort - to be usable with IS on in all cases. On monopods, too. There's almost always enough movement, even if it's very slight, for IS to have something to keep it occupied.
Occasionally you might have a problem with a lens that's got the less sophisticated type of IS... Heck if you do a really, really good job handholding it's possible for the IS to act up. But it would likely be a pretty rare occurance and you can see it in the viewfinder, when it occurs.
I've been shooting with IS lenses for about 12 years - some from both lists - and I literally can't recall the last time I actually turned IS off. Now, it so happens that the lenses I have where you're supposed to, I use mostly for handheld shooting. One, though - my 300/4 IS - I do put on a monopod sometimes during long, long shooting days... and have never seen any issues at all with it. I also should note that I don't find reason to shoot long exposures very much, at least not with any of my IS lenses. And I don't shoot video with my DSLRs. Both are situations where you might want (need?) to turn off IS. And, yes, it's true that you might save a little battery charge by turing off IS. IMO, it's very little savings. If working right, IS just doesn't seem to consume all that much power. I sometimes shoot all day with IS operating "nearly continously". For example, dressage shows (equestrian) involve nearly constant tracking and following the subjects, one right after another, usually 8 hours of shooting minimum at major events, and a pair of LP-E6 batteries will typically still have juice remaining after taking 2500 to 3000 shots. IS and AI Servo AF are running nearly the full time, though I do conserve batteries in some other ways (never use the on-board flash, minimize image playback, shortest possible duration to sleep mode, etc.)
Note if you are panning and wanting a background blur effect, some lenses have two-mode IS. Mode 1 stabilizes in both vertical and horizontal directions. Mode 2 is for panning and only stabilizes the vertical axis, doesn't try to counteract horizontal movement. (The lens senses the way you are holding the camera, in landscape or portrait orientation, and will apply the above appropriately in either case.)