IN-BODY IMAGE STABILIZATION (IBIS) UPDATED

[MagRat Garlic]

There seems to be a lot of confusion about what Image Stabilization is, what it does, and what it doesn't do. It's a subject that keeps coming up in the livestreams so, until Rob gets around to releasing his YouTube video on IS, here's a brief explanation.

Please note that this article has been updated with links to Robin Wong's two videos on Image Stabilization, which I've now added at the end of the article.

Image Stabilization helps remove the blurring effect of camera shake during long exposures of Still images.

If you're taking hand-held photographs with a long exposure speed -- say longer than 1/30th of a second -- or you are using a long telephoto lens with a relatively slow shutter speed, then there's a good chance that the camera will shake a minute amount during the exposure. This will result in a blurring of the image as it's seen by the camera's sensor.

But, what if the camera was able to detect that camera shake and what if the camera moved its sensor, vertically and horizontally, so that the sensor remained aligned to the image throughout your long exposure? Well, that's precisely what In-Body Image Stabilization (IBIS) does.

The Olympus OM-D series cameras can detect camera shake through their accelerometers. The camera is able to detect camera shake on 5 different axis. It will then move the image sensor a minuscule amount during the exposure (i.e. WHEN the Shutter is Open) so that the sensor's minuscule movements counterbalance the minuscule movements of your camera shake.

That's it. There's no digital magic of somehow "electronically freezing" the image. What's seen through the lens still shakes about*, but the camera's electronics tell the sensor to shake itself in sympathy with your camera shake and so balance it out.

(*remember, I'm talking about the Olympus' In-Body Image Stabilization (IBIS) and not about In-Lens Image Stabilization. We'll talk about that another time. This article is also concerned with stills photography, and should not be confused with the slightly different image stabilisation used in video mode.)

Now, it's important that you note I'm saying that IBIS is there to cancel out "camera shake". And that you understand that camera shake is the very small hand movements that are inevitable if you're hand-holding a camera during a long exposure. This is entirely different from you making large intentional movements -- such as panning in wildlife or sports photography.

Because IBIS needs to physically move the sensor to cancel out the microscopic movements of camera shake, it works for tiny vibrations in camera shake. But, if you go panning your lens to track a Formula 1 race car or a football player running across the pitch, and you've left Image Stabilization turned ON, then you're asking your camera to move its sensor a huge amount to compensate for that massive movement. It's physically impossible for your camera to do this.

What will happen if you pan your camera in FULL IBIS mode is that the camera's accelerometers will detect the horizontal movement. The camera's electronics will instruct the sensor to move to compensate. The sensor will move to the maximum (minuscule amount) its motors permit, then stop moving. The camera will recognize that it has an out of parameters exception, and refuse to even think about allowing a shutter release until the sensor has repositioned itself. As such, Sequential Shooting and Autofocus are disengaged until the sensor has finished repositioning itself. And, if the accelerometers detect you're continuing to pan the camera, the sensor will continuously attempt to reposition itself, thus you've totally confused your camera.

Ok, but what if you want IBIS while you're panning? Well, remember what I said right at the beginning, "Image Stabilization helps remove the blurring effect of camera shake during long exposures of still images". Ask yourself: are you photographing at slow shutter speeds; because IBIS is only useful if you're shooting still images with long exposures (below 1/30th of a second, I suggested). In this case IBIS will be helpful to counteract any vertical shake. Whereas, if you're exposures are between 1/60th to 1/125th of a second, you should be ok with a careful hand-held exposure and it doesn't make any difference if IBIS is ON or OFF, but if it's ON, you may experience delays while the sensor is repositioning itself. Above 1/250th of a second, and you don't need IBIS except where you're using a super-telephoto lens in exceptional circumstances; so best to have IBIS switched OFF.

If you know you'll be shooting at high shutter speeds, it's best to set IBIS OFF, as it's one less thing that the camera's limited processing capability needs to think about, when you want every bit of your processor devoted to Sequential Autofocus.

Ah, but what about AUTO IBIS, FULL IBIS, and those other two IBIS settings in the menu? Let's take a look:

AUTO IBIS is the default setting of your Olympus camera. In the default AUTO IBIS setting, your camera continuously monitors its accelerometers for excessive panning movement in the horizontal (or vertical) plane. By this I mean movement that is greater than the involuntary camera shake movements, which your camera will interpret as you intentionally moving the camera to pan after a subject. If such movement is detected, then the camera's electronics will ignore that particular accelerometer until the shutter button is released.

Let's say AUTO IBIS detected horizontal panning, then the horizontal movement accelerometer will be ignored. The sensor will no longer attempt to compensate for any horizontal movement. But, the other accelerometers will still be monitored, and any vertical camera shake will activate movement of the sensor to compensate for minuscule vertical plane camera shake.

Do you need IBIS in any plane when you're panning? Probably not. The smooth muscle action of panning is usually enough to inhibit any camera shake. Also, remember that with any of the IBIS modes you're giving your camera's processor extra work to do, and that will slow Autofocus and Sequential shooting speeds. As such, Olympus gave you two other modes for controlling IBIS.

The two other IBIS modes allow you to tell your camera's processor that you intend to pan the camera. This saves the processor having to figure out what you're doing, as you are manually switching off one of the accelerometers. One of these modes is for panning in landscape orientation. The other is for panning in the portrait orientation. (In other words, they're both intended for horizontally panning the camera, and which one you choose depends upon whether you're using the camera in landscape or portrait orientation.) This is important, as Olympus expects you to be panning horizontally. So you can use AUTO or one of these two options to pan with selective IBIS. Personally, if I'm panning, I select IBIS OFF.

When does IBIS start moving the sensor to compensate for camera shake? It begins when you half press the shutter button. IBIS monitoring of the accelerometers (and sensor repositioning) is cancelled when you take pressure off the shutter button.

I've said that IBIS is there for when you are taking Still images with long exposure times. A "still" image is where the subject is not moving. IBIS won't magically "freeze" a subject that requires a long exposure. Some people think it works like image stacking, where the camera takes one under-exposed frame, then multiplies that one exposure to reach the correct exposure level. Sorry, it doesn't do that. IBIS has no effect on the usual problem of selecting an appropriate aperture and shutter speed to give a correct exposure. It simply cancels out minute vibrations, termed camera shake, during long exposure times.

Finally, let's look at using IBIS to capture birds and aircraft in flight. Ok, you're probably using a relatively high shutter speed. However, if you're using a super-telephoto lens, you might appreciate some help with Image Stabilization to compensate for lens shake. The good news is that IS can be used with telephoto lenses, but the bad news is that it'll give you problems if you are panning both horizontally AND vertically (or diagonally).

Remember that IBIS is about eradicating camera or lens shake. We can tell the camera to ignore one of its sensors, for landscape or portrait orientation panning, but that's no help if our bird or plane is flying diagonally towards us. Your only option is IS OFF.

RECCOMENDATIONS:
• AUTO IBIS if you're out and about not sure what you'll be snapping.
• FULL IBIS for posed photographs where you're guaranteed no movement of what you're photographing, such as product photography.
• OFF (NO IBIS) for birds or aircraft in flight (as well as ALL tripod work).
• MODES for when you know the direction you'll be panning and can guarantee there will be no diagonal panning.

Please post any questions in the Replies below. I will do my best to answer them.

This is a first draft of my explanation. I'll edit and improve it if you tell me which bits you don't understand. Without your feedback I'll not know where to improve my explanation. So don't hesitate to ask about anything that isn't totally clear.

Have fun, and I hope this gives you a better understanding of how Image Stabilization works.

As mentioned at the beginning of this article, Robin Wong has released two videos on Olympus' Image Stabilization; you are advised to watch both of these videos after reading this article.


in particular, you should watch out for Robin's comments on:
• using Panasonic's Lenses (where Panasonic put the IS in the lens as versus Olympus' in-body IBIS) and how this works when a Panasonic lens is attached to an Olympus OM-D or Pen-F body ;
• the surprising behaviour of the IS on/off switch on the Olympus' 12-100mm f/4 PRO and 300mm f/4 PRO lenses ;
• use of the IBIS modes previously discussed, above ;
• using either of the Olympus Teleconverters MC-14 or MC-20 ;
• understanding differences in IBIS between the various OM-D series camera bodies.

Bye for now,
MagRat

(Rick's feral pussycat.)

[1957PLATO]

Thanks, Rik.

Very clear explanation.

[deboco]

Thanks Rick, very well written. I think I will needs lots of practice!

[Pauline0111]

Thanks for the above, I understand all the IBIS options but somehow every time I take a picture, the info shows me that IS is OFF . However when I look in camera, under the INFO, the IS is on. I have two lenses - the 12-40 f/2.8 pro and the zoom kit lens 40-150 f/4:5.6. None of these lenses have lens IS, and the OM-D e Mark10 II does not have 5-axis sync so it cannot (I think) be the non-sync settings between lens and body.
I would assume that the IBIS I set, would apply for all my lenses. ( I usually have IS-S 1)
However in Workspace all pictures say the IBIS is Off. I must be doing something wrong but what?
Any help would be appreciated!! thank you