Canon R5 Autofocus/IBIS problem - Sensor locking

[adamofa2]

Hey All,

I'll preface this by saying I've shot with EOS DSLRs for over 15 years and this problem has only happened with my mirrorless R5. I never had this problem with my DSLR lineup including the Canon 5D II and 20D/40D cameras.

When using my Canon R5 + RF 100-500 to shoot I'm frequently getting photos where the camera incorrectly focuses on the background and not the foreground subject I'm shooting. In these examples I'm panning with the subject with the autofocus set to SERVO and LARGE ZONE AF: HORIZONTAL and the autofocus points (Blue boxes, white box that turns blue) are bouncing around over the subject aircraft. Yet, the autofocus will incorrectly focus on the background and seemingly lock the sensor in place relative to the background, making it look as though I wasn't panning at all and instead the object passed through the frame while shooting a fixed position off a tripod. This error happens through an entire sequence of photos while tracking a subject.

Are there any photographers here who shoot motor sports, aviation, or sport and have experienced this bizarre autofocus/ibis issue?

[ATTACH alt="Notice how the "5" Sign and runway light stick (below the aircraft on the edge of the runway) is crisp and in focus, yet the aircraft is blurred. 1/500, f/8.0, ISO125, 500mm, Aperture Priority, Pattern Metering"]2990537[/ATTACH]
Notice how the "5" Sign and runway light stick (below the aircraft on the edge of the runway) is crisp and in focus, yet the aircraft is blurred. 1/500, f/8.0, ISO125, 500mm, Aperture Priority, Pattern Metering

For the non-aviation/motor sport shooters who might be reading this: the rate of pan required to shoot a flying aircraft is not as fast as you think. Here's another example featuring the autofocus/ibis error where the aircraft was only rolling by at perhaps 15 mph. So, I expect if I get any replies from you guys there'll be critiques that I need to work on my panning. Again, I never had this problem when panning with DSLRs. I'm 99.9% sure this is a technology issue and not a result of me suddenly being unable to hold my camera.

Here's one more, featuring an aircraft that was just rolling by at 10-15 mph. At about a panning rate of 5-10 degrees per second.

f/7, 1/400, ISO160, 500mm, pattern metering.

Notice how the autofocus of the camera "locked" onto the grooves in the asphalt, freezing the movement of the panning camera resulting in a blur of the aircraft onto which I was tracking with the autofocus.

I called Canon Support and the technician suggested it might be a result of a battle between the IBIS and Lens IS and I should turn off the Lens IS (Well then what's the point of having the IS! I paid good money to have IS on my 500mm lens!)

These were taken with the following firmwares installed:

1.0.9 on the RF100-500

1.3.1 on the R5

I updated both firmwares this morning before making this post, but neither updates mention an upgrade to IBIS/Autofocus ability so I don't think old firmware was the cause of the problem.

Any help or guidance is appreciated!

 

[Steve Balcombe]

I guess it depends on your definition of motion blur. If the camera was stationary and the aircraft was passing THROUGH the frame as the exposure was taken, yes, this would be motion blur of the plane.

Motion blur is of two kinds - subject motion blur (camera is static, subject moves); and camera motion blur, often called camera shake blur (subject is static, camera moves). It's not uncommon to have both types of motion blur in the same image.

But we need to define 'camera motion' more precisely to take image stabilisation into account. The camera may be outwardly moving, but the image stabiliser has detected the motion and either moved a lens element/group to shift the image and keep a static subject in the same place on the sensor even though the camera moved slightly, or moved the sensor itself to achieve the same objective. The first is optical IS, the second is IBIS. It is also possible for the two systems to coexist and cooperate, as with the RF 100-500 on the R5. But whichever, if the IS succeeds in holding the image in the same place on the sensor, we have no camera motion blur. If it fails, we have camera motion blur i.e. camera shake.

The opposite happened when the exposure was taken. The camera was panning with the aircraft while the background (runway pavement) was passing through the frame in a linear motion. So, when the exposure was taken, for some odd reason (and this is the point of this whole post) the runway was sharp and the aircraft was blurred. Why though? That is the question.

That is the question, but it has already been answered multiple times. We can incontrovertibly see that there is sharp ground both closer than the plane, and further away. We can therefore totally rule out any sort of focusing issue - it is impossible to have two sharp distances with an unsharp distance in between, since that would be two focusing distances.

So the only possibility is some kind of motion blur, we just have to work out how it happened. Well, there are two and only two possibilities:

1) You didn't pan smoothly, stopping momentarily when the shot was taken. The ground is static, the plane was moving, hence what we see. Let's give you the benefit of the doubt and assume that didn't happen!

2) The image stabiliser tried to combat the camera motion, and succeeded, so that the ground remains in the same place on the sensor despite the camera movement. Static subjects are sharp, moving subjects have motion blur. This is what happened and we have whittled this down to deciding how. There are once again only two possibilities:

2a) You were using Mode 1, which will hold a static subject in the same position on the sensor until you reach its operating limit; or

2b) You were using Mode 2, which is intended to detect panning movement and disable IS in that direction only, but the movement was not detected. Maybe it was too slow; maybe it was too irregular; maybe the IS needed more time to establish that you were panning. We can't rule out this being due to a fault (Mode 2 behaving like Mode 1), but at this point in time I have no reason to suspect that.

If you were definitely using Mode 2, but you are not getting good results, the next step is to turn off IS. After all, the whole point of Mode 2 is to automagically turn off IS in the horizontal direction, while still giving you some up-down stabilisation. In Mode 2 it is entirely your responsibility to correctly follow the movement of the subject so there is no horizontal blur of the subject. IS does not help you with that. If your technique is good enough to do that successfully, then you quite likely don't need any help holding the camera steady with respect to up-down motion. Therefore you can turn IS off with little or no penalty.

--
https://www.flickr.com/photos/stevebalcombe/ or
http://www.flickriver.com/photos/stevebalcombe/popular-interesting/

 

[SigZero]

These were taken with the following firmwares installed:

1.0.9 on the RF100-500

1.3.1 on the R5

Few days ago Canon published 1.1.0 for 100-500 - always worth trying, although changes are related to R3 Electronic shutter.

Br, Pawel.