amfoto1 wrote in post #18463587
I have no idea why anyone would "avoid using AI Servo with non-IS lenses". I've never even given it a thought before and use it with both. Focusing and images stabilization are two different systems that don't have very much interaction. And in fact, after using various IS lenses for over 15 years, if anything I think Canon IS "helps" the camera & lens focus more quickly (regardless of mode), by stabilizing the target that the AF system is trying to lock onto. But all that's neither here nor there with non-IS lenses.... I see no reason not to use AI Servo with them, too. Works fine!
Most of my AI Servo experience, IS lens preference, comes from my experience of trying to get repeated sharp images with the 50 megapixel 5DSR. Your comments about IS helping is actually making my point for me - and what I learned after months and months of testing trying to find the best working lenses for the 5DSR - and realizing how important a stable platform is - and why, paradoxically, AI Servo, with its repeated firing of the AF mechanism, hurts the stability platform - and why that is extremely detrimental when using a high megapixel camera and trying to extract the maximum resolution.
I don't in anyway believe that my comments above are relevant to this thread - but I have answered them, for you, to tell you why I never, ever, will use AI Servo, with a 5DSR, while handholding, unless the lens has IS - but more importantly, I don't use any lens, on the 5DSR, that doesn't have IS - I in fact sold the 35L, 50L, 85L II and 135L because after months of testing, every way to Sunday, I determined, and have enormous amounts of data to prove it, that you need 1/6x FL to get tack sharp images on the 5DSR when lenses do not have IS - and that AI Servo makes the problem worse, not better, than Single Shot. As an aside, I have replaced all the above lenses with the Tamron 45 & 85 1.8 VC and I'm waiting for the Canon 135L IS to be released - and can tell you that there is no comparison for handheld sharpness. In comparison, for my 20 megapixel 1DXii, I use the 24-70 F2.8 II, and the Canon 35Lii F1.4 and the images produced are tack sharp for 20 megapixels - but basically useless when trying to extract 50 megapixels of detail - thus I am waiting for delivery of my Tamron 24-70 F2.8 VC.
Hockey and wedding photographer. Favourite camera / lens combos: a 1DX II with a Tamron 45 1.8 VC, an A7Rii with a Canon 24-70F2.8L II, and a 5DSR with a Tamron 85 1.8 VC. Every lens I own I strongly recommend [Canon (35Lii, 100L Macro, 24-70F2.8ii, 70-200F2.8ii, 100-400Lii), Tamron (45 1.8, 85 1.8), Sigma 24-105]. If there are better lenses out there let me know because I haven't found them.