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    Image Stabilization

    I have been asked a question via PM, when to use and not to use IS. That could have been a couple of sentences answer, but I have had many conversations with other photographers where, although they were near enough right with the use of IS, they didn’t really understand what or why. So I thought a more in depth answer may be of some benefit to other Forum members.


    Why the need for Image Stabilization?

    The human body is always moving …………. assuming you are not deceased! That is through voluntary movement, breathing and involuntary movement, which the body is always subject to. If you use a slow shutter speed, these voluntary and involuntary movements will cause your images to be unsharp. Before Image Stabilization, the advice was to use a tripod, or use a shutter speed at least the reciprocal of the lens you intended to use. So, for a standard 50mm lens the reciprocal would be a minimum shutter speed of 1/50thsec or above. A 200mm lens would need 1/200thsec or above and a 500mm lens would need at least 1/500thsec or above. Note that a 500mm lens needs 10x the shutter speed of a 50mm, because the higher magnification of the 500mm also magnifies the amount of camera shake by a factor of 10.


    How does Image Stabilization work?

    Image stabilization is designed to minimize camera shake, but it cannot eliminate it. There will still be occasions when you need to use a tripod and a remote release. Early systems could minimize camera shake by two stops, so for example if you were using a 200mm lens, instead of needing 1/200thsec under the reciprocal rule, using IS you could get away with 1/50thsec. The newer IS systems claim up to four stops and that would mean a minimum shutter speed of around 1/15thsec, though I haven’t actually tried it. At that speed I would already have the tripod out.

    There are two types of IS: in-camera and in-lens and in my opinion, in-lens is superior, because each lens can be optimized for best performance, whereas in-camera is a compromise for all of the lenses that could be used on that body. It works by using two small gyroscopes within the lens, one to minimize horizontal movement and one to minimize vertical movement. If you are panning a subject, you can switch off the horizontal gyro so that only the vertical movements are corrected. Early IS systems could also provide soft images if IS was switched on, but the camera was on a tripod. The IS was trying to correct camera shake when there wasn’t any present and by default, sometimes introduced some shake into the shot. Later systems have electronics that detect when camera shake is not present and switches it off.


    When to use Image Stabilization?

    This is to answer the original PM: when to use it and when not to. These are my thoughts, although I am aware that many keep it switched on all the time ………. just in case!

    By its very nature, IS mitigates camera shake and has no effect whatsoever on the movement of the subject. My photography is mostly birds in flight and generally, I am using a shutter speed between 1/1,000thsec and 1/2,000th sec. Probably more for Kingfishers, humming Birds etc. So, for a 500mm lens, my shutter speed is well above the threshold for the reciprocal of the lens, so I switch IS off. What’s the point of trying to correct a problem that isn’t there? Equally, any fast sports action, motorsport and fast jets I will not use IS. For propeller driven aircraft I want some prop blur, so I will bring the shutter speed down to 1/250thsec to get a few shots in the bag and once that is achieved, I will adjust the shutter to 1/125thsec and maybe 1/60thsec for even more prop blur. Because all of those shutter speeds are below the reciprocal of the lens, IS will be switched on. The same with some motorsport shots where I want the body sharp, wheels blurred and motion blur in the background. I also have IS switched off when using a tripod, beanbag, or monopod.

    Conclusion

    I hope I have answered the original question and the above is of some use to other members. May I advise that these are only my thoughts and I may well be wrong on some aspects. If so, I am more than happy to learn from you.
    Colin

    #2
    Re: Image Stabilization

    An excellent response to an often asked question.

    I can add no more other than to say that modern cameras and lenses are highly sophisticated pieces of equipment but at the end of the day only a tool to capture images. We do not need all the sophistication all the time but it's good to know it's there if it helps us to achieve what we want.
    I'm old enough to remember the reaction of photographers when auto focus was introduced and when no future was seen for digital technology.
    My own view is embrace & use the technology but remember the most important factor is the photographer.
    I can talk to my car so how long will it be before we hold a conversation with our cameras?
    All I'm wanting now is 'Auto Composition', believe me it'll come!
    Bob


    EOS 6D mkII, EOS 6D, BG-E13 Grip, EOS 30 (Film), EOS M5, EF-M 22mm f2.0, EF-M 18-150mm, 35mm f2.0 IS, 50mm f1.8 STM, 17-40 f4 L, 24-105 f4 L IS, 70-200f4 L IS, 430EX II, 270EX II, Manfrotto 190XDB +496RC2 tripod, Op Tech straps & Think Tank bags.

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      #3
      Re: Image Stabilization

      It's fully auto tracking for me Bob. That would make my work a lot easier.
      Colin

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        #4
        Re: Image Stabilization

        I have never switched the is off , not even used the switch to turn it off when transporting, which no one told me about until I read about it on a thread on here. I hope to be getting another lens in the sales next week, I must get in the habit of using the switch.
        Hanging on in quiet desperation is the English way

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          #5
          Re: Image Stabilization

          One thing to remember is that if there are two (or more) IS modes, make sure you have the right one selected. When I first got my Sigma 100 - 400 C, I thought it was hopeless as the image kept jumping about in the viewfinder. However, I then discovered that the IS switch had been moved to position 2, which is only for panning, and I assume it was trying to correct for non-existent panning movement. Once I turned it to position 1, the problem disappeared.

          Most lenses when tested very critically don't consistently provide the number of stops improvement they claim, look on Lenstip reviews to see. The latest Canon lenses are much better, the EF 100-400 mm f/4.5-5.6L IS II USM and (fairly low priced) EF 70-300 mm f/4-5.6 IS II USM both do give the rated 4 stops and it's an area where Canon seems to have the edge over the others.

          IBIS is mainly important for video, to quote Digital Photography Review "There may have been little difference in performance between in-lens and in-body stabilization when it came to stills, but the same can't be said for video. Watch TV or movies and you'll see all sorts of camera movements, but what you won't tend to see is roll: left-and-right rotations that cause the horizon to tilt. In-lens stabilization can correct for pitch and yaw but it can't correct for roll: which gives in-body stabilization an immediate advantage."

          Personally I now mainly use shortish focal length (up to 135 mm) prime lenses, only one (the EF-S 35) has IS and I don't miss it in the least. Even though I also keep ISO at no more than 400, it's still easy to use an adequate shutter speed. We all did it for years, those of us who are old enough anyway.
          EOS 6D, 6D Mk II, 80D, 70D, 100D, 200D, M50, M100. Canon 10-18, 18 - 55, 55 - 250 IS STM lenses, Canon 16 - 35 mm F4L, 35 mm EF-S macro, 50 mm F1.8 STM, 60 mm EF-S macro, MPE-65 macro, 85 mm F1.8, 200 mm F2.8 L II, M 15 - 45 mm, M 22mm F2, M 32mm F1.4. Sigma 24 - 35 F2 Art, 135 mm F1.8 Art, 17 - 50 F2.8 DC, 105 mm OS macro, 100 - 400 C, 150 - 600 C.

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            #6
            Re: Image Stabilization

            Interesting discussion. I'm a bit of an old git with none too steady hands so need all the help I can get. Where possible I do tend to try and keep shutter speed high enough so that IS isn't the prime reason for obtaining sharp images.

            Generally I don't turn IS off except when tripod mounted, I know Canon lenses are suppose to detect if on a tripod and turn it off but not sure about my Sigma 150-600 C.

            Do remember photographing goldcrest in shadow and getting sharp images at 600mm on my 5D3 with shutters speeds of 1/90 and 1/60 sec. Without IS don't think this would have been possible.
            Canon 5D3, 7D2, 60D, Canon 70-200L f2.8 IS II, Canon 300 f4L IS, Canon 16-35 f4 L, Canon 24-105mm f/4L IS USM, Canon 1.4 MkIII extender, Sigma AF 10-20mm f/3.5 EX DC HSM, Sigma 150-600 Contemporary, Tamron SP AF 70-300 F/4-5.6 Di VC USD, Canon EF-S 18-55mm 1:3.5-5.6 IS
            https://www.flickr.com/photos/16830751@N03/

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              #7
              Re: Image Stabilization

              Great thread - thank you Colin

              Brian
              ef-r

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                #8
                Re: Image Stabilization

                Great thought provoking thread Colin - thanks. I will familiarise myself where the IS switch is and experiment
                Cheers
                Dave

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                  #9
                  Re: Image Stabilization

                  IMHO IBIS is more important in Mirrorless cameras where there seem to be more people that want to use adapted lenses - the stabilisation applies regardless of the lens so you can stick that old Pentax M42 lens you love on an adaptor and then on your mirrorless camera and it's stabilised.

                  I think the other area where IBIS wins is when you want to keep the cost of lenses and their size down. For the user, you either pay once to have IBIS in your camera or multiple times to add it to your lens collection and lenses without it tend to be smaller and lighter than stabilised equivalents. I suspect this is why a lot of manufacturers have gone down the IBIS route, the cost to them is lower which means they can protect their margins...

                  Like Richard though, a lot of my lenses are now non-IS - with focal lengths from 12mm to 35mm - so I keep my shutter speed up. But that doesn't mean I don't use IS on my 100-400mm when I'm out for wildlife.
                  EOS 7D mk II, Sigma 150-660C, Canon 17-85 EF-S, Tamron 10-24 and a wife who shares my obsession.

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