setagate wrote in post #18704741
If I buy a 100-400 L IS lens, and I believe I will, I will be using IS. I don't see how it can hurt and I expect it would help
Contrary to what one other responder says...
Canon IS is very effective and extremely helpful. I've been using a number of different lenses with IS for over 15 years, have made hundreds of thousands of images with it, and can assure you that it improves images far more often than not, and virtually never "hurts" an image. I almost never turn IS off. Especially when shooting hand held and especially when using telephoto lenses. In fact, IS was one of the top reasons that I (and many others... look at photos of the the sidelines of any major sporting event) switched to the Canon system many years ago. IMO Canon IS improves focus performance and even stabilizes the image in the viewfinder to some extent, which can be helpful when panning shots.
I considered the EF 400mm f/5.6L USM in the past and "took it for a test drive".... But ended up buying the EF 300mm f/4L IS USM instead for two reasons: One being that it works very well with a quality 1.4X teleconverter, giving me both a 300mm f/4 and a 420mm f/5.6.... The other over-riding factor being that 300mm has IS and the 400mm doesn't. The reason I was considering these lenses was to have a hand holdable telephoto to complement 300mm f/2.8 IS and 500mm f/4 IS that I already had, but are largely "tripod only" lenses that make me less mobile. Ultimately, I use the 300mm f/4 so much that I ended up buying a second one as a backup.
I also considered, tried out, but didn't buy the original 100-400mm. I just am not a fan of push/pull zooms like that (I know some people like em, tho). It was a fine lens, aside from that and one other minor thing. For some reason, it's highly sensitivity to filters... putting any filter on the original 100-400 causes it's images to "go soft"... even when it's an ultra high quality, multi-coated filter. I don't know why that's the case, but a lot of users of that lens were stunned to learn how good it was, after they removed the "protection" filter they'd put on it since new. The filter "issue" didn't matter to me, though, since I rarely use any filter on telephotos like these.
A couple years ago I got the 100-400mm II and now use it most... though it's a bit bigger and heavier than the 300mm f/4 (3.5 lb. vs <3 lb.). Still, it's hand holdable for a fairly long time... only during 4, 6 and 8 or more hour long shooting sessions I might put it on a tripod with a gimbal head. Note: the 300mm f/4 uses an earlier form of IS that can cause problems when locked down on a tripod.... same with the original 100-400mm "push/pull" zoom. It's generally not a problem when working with a loose gimbal, though. Plus the whole point of those lenses is hand-holdability. This is not an issue with the 100-400mm II. It self-detects and automatically turns off IS, when there's no movement to correct, such as when locked down on a tripod.
Even since getting the 100-400, I still switch to the 300mm f/4 at times, when shooting in lower light conditions where the extra stop is helpful. There are a couple indoor venues I shoot regularly where the f/4.5-5.6 zoom requires a little too high ISO or a little too slow shutter speed to freeze subject movement. The variable aperture of the 100-400mm II starts out at f/4.5, drops to f/5 at 135mm, but then maintains that to just over 300mm, where it finally drops to f/5.6 (far better than Tamron or, especially, Sigma 100-400). But even though it's only 2/3 stop difference up to 300mm, when light is marginal, I'll use the f/4 prime instead (or if even worse light, f/2.8 prime even tho it means a tripod for anything longer than a few minutes). This isn't a factor, though, when comparing the 100-400 to the 400mm f/5.6. In fact, at shorter focal lengths the prime doesn't even offer, the zoom has 1/3 to 2/3 stop advantage.
Besides.... If Image Stabilization were so bad and problematic... if users didn't think it worked very well.... why did every camera and lens manufacturer scramble to follow Canon's lead and implement it in their respective lenses and cameras? Some took 8 or 10 years to catch up... but they all stabilize everything now.
There are differences between different manufacturers' stabilization systems. Obviously, some use in-camera instead of in-lens stabilization. But, even beyond that, each manufacturer has patented their system... So even though the ultimate goal is the same, there are bound to be some differences. For example, it's widely thought and pretty well proven that Nikon "VR" slows autofocus to a certain extent and a lot of folks shooting with their lenses turn it off for that reason. I don't believe same isn't true of Canon IS... in fact, if anything I think it assists and speeds up autofocus. I have no way of testing and roving this.... it's just based on fifteen + years experience.
There also have been examples of lenses that were "softer" in stabilized versions... Tamron's 17-50mm f/2.8 "VC", for example, is noticeably less sharp than the non-VC version. But this most certainly isn't true of most Canon lenses. In fact, in many cases the IS lenses are sharper than the non-IS.... compare the EF 70-200mm f/2.8L non-IS to any of the three f/2.8 IS versions or the two f/4 IS versions.... all of which are notably sharper than the non-IS version (which is an old design, but still in production as a lower cost alternative).
Image quality... sharpness, contrast etc.... is nearly identical. No worries with either lens. See for yourself:
All these lenses are quite well built, like most L. The guys at Lensrentals like to take things apart just to see what's inside, and when they did a tear down of the 100-400 II they called it "the best built zoom they'd ever seen". (That was before Canon released the 200-400mm f/4L Extender, though.) The 100-400 II is a much newer lens and probably has better sealing than the older 400/5.6L, too. However, the 100-400 II is not internal zooming... it increases in length considerably and this probably reduces it's weather resistance to some extent. The 400/5.6L, on the other hand, is internal focusing.... probably easier to seal up. So I would guess that it's pretty much a wash.
The 400/5.6L also has a built in lens hood... that's nice and convenient. Always right there and ready to use. The 100-400 II's hood is separate and reverses for storage on the lens, but is the new design Canon has been using on all their lenses, with the improved locking mechanism (and higher price tag, if it's ever lost). Oh, and the 100-400 II's hood has a little door in the underside to give access to rotate a filter, if needed.
So in answer to your original question... I'd buy the 100-400 over the 400mm f/5.6. Even some years ago I chose an IS lens over the non-IS 400mm f/5.6L. And I'd do the same again today. It's more money, of course, but the versatility of the zoom that the 100-400mm II offers is also very worthwhile. And it's IS is among the "latest and greatest" types... with 3-4 stops worth of assistance and near instant action.... the lens is also quite fast focusing and works well in hand. Canon wisely put the big zooming ring forward on this lens (opposite many of their other zooms, such as the various 70-200s), where the lens rests in your hand when shooting with it.
One minor short-coming of the 100-400mm II is it's tripod mounting foot, which is designed to be easily removed. It's a nice looking "curvaceous" design.... which doesn't mate well with the anti-twist features of Arca-Swiss quick release lens plates! If using the Arca QR system, I recommend replacing the tripod mounting foot completely. There are quality replacements with built-in Arca QR dovetail from Kirk Photo, RRS, Hejnar Photo and some others. These cost a little more than a lens plate, but are well worth it. They all also fasten using a hex head screw that I feel more confident about than the thumb-screw that Canon used on the OEM foot. (I ended up buying the Hejnar foot for my 100-400 II. The other two are fine, too, I'm sure. There are now some cheaper knock-offs avail., I'm not sure about those.)